From c0701537b68492a1ba7473c4905fddf8e4d50ffe Mon Sep 17 00:00:00 2001
From: Joel Wetzell <git@jwetzell.com>
Date: Sat, 30 May 2026 08:56:07 -0500
Subject: [PATCH] remove constants from packet structs

---
 address.go         |  36 +++----
 command.go         |  41 +++-----
 datarequest.go     |  41 +++-----
 diagdata.go        |  37 ++-----
 dmx.go             |  52 ++++------
 dmx_test.go        |  76 ++++-----------
 ipprog.go          |  33 ++-----
 ipprog_test.go     |   4 -
 ipprogreply.go     |  33 ++-----
 nzs.go             |  37 ++-----
 packet.go          |   1 -
 poll.go            |  33 ++-----
 poll_test.go       | 235 ++++++++++++++++++++++++---------------------
 pollreply.go       |  22 ++---
 sync.go            |  37 +++----
 timecode.go        |  51 ++++------
 timecode_test.go   |  34 +++----
 todrequest.go      |  57 +++++------
 todrequest_test.go | 180 +++++++++++-----------------------
 trigger.go         |  27 +++---
 20 files changed, 389 insertions(+), 678 deletions(-)

diff --git a/address.go b/address.go
index 5d8cb3c..008e918 100644
--- a/address.go
+++ b/address.go
@@ -85,10 +85,6 @@ const (
 )
 
 type ArtAddress struct {
-	ID          [8]uint8
-	OpCode      uint16
-	ProtVerHi   uint8
-	ProtVerLo   uint8
 	NetSwitch   uint8
 	BindIndex   uint8
 	PortName    [18]uint8
@@ -101,15 +97,7 @@ type ArtAddress struct {
 }
 
 func (aa *ArtAddress) GetOpCode() uint16 {
-	return aa.OpCode
-}
-
-func (aa *ArtAddress) GetProtVer() uint16 {
-	return uint16(aa.ProtVerHi)<<8 + uint16(aa.ProtVerLo)
-}
-
-func (aa *ArtAddress) GetID() [8]uint8 {
-	return aa.ID
+	return OpAddress
 }
 
 func (aa *ArtAddress) UnmarshalBinary(data []byte) error {
@@ -117,16 +105,14 @@ func (aa *ArtAddress) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtAddress packet must be at least 107 bytes long")
 	}
 
-	copy(aa.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], aa.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	aa.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	aa.ProtVerHi = data[10]
-	aa.ProtVerLo = data[11]
-
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpAddress {
+		return errors.New("packet does not have the correct OpCode for an ArtAddress packet")
+	}
 	offset := 12
 	aa.NetSwitch = data[offset]
 	aa.BindIndex = data[offset+1]
@@ -141,11 +127,11 @@ func (aa *ArtAddress) UnmarshalBinary(data []byte) error {
 }
 
 func (aa *ArtAddress) MarshalBinary() ([]byte, error) {
-	data := make([]byte, 8+11)
-	copy(data[0:8], aa.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], aa.OpCode)
-	data[10] = aa.ProtVerHi
-	data[11] = aa.ProtVerLo
+	data := make([]byte, 8+99)
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpAddress)
+	data[10] = 0
+	data[11] = 14
 	offset := 12
 	data[offset] = aa.NetSwitch
 	data[offset+1] = aa.BindIndex
diff --git a/command.go b/command.go
index 22785fd..74dbcd9 100644
--- a/command.go
+++ b/command.go
@@ -14,28 +14,12 @@ const (
 )
 
 type ArtCommand struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	EstaMan   uint16
-	Data      []uint8
+	EstaMan uint16
+	Data    []uint8
 }
 
 func (ac *ArtCommand) GetOpCode() uint16 {
-	return ac.OpCode
-}
-
-func (ac *ArtCommand) GetProtVer() uint16 {
-	return uint16(ac.ProtVerHi)<<8 + uint16(ac.ProtVerLo)
-}
-
-func (ac *ArtCommand) GetID() [8]uint8 {
-	return ac.ID
-}
-
-func (ac *ArtCommand) Length() uint16 {
-	return uint16(len(ac.Data))
+	return OpCommand
 }
 
 func (ac *ArtCommand) UnmarshalBinary(data []byte) error {
@@ -44,15 +28,14 @@ func (ac *ArtCommand) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtCommand packet must be at least 16 bytes long")
 	}
 
-	copy(ac.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], ac.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	ac.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	ac.ProtVerHi = data[10]
-	ac.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpCommand {
+		return errors.New("packet does not have the correct OpCode for an ArtCommand packet")
+	}
 
 	offset := 12
 	ac.EstaMan = binary.BigEndian.Uint16(data[offset : offset+2])
@@ -69,10 +52,10 @@ func (ac *ArtCommand) UnmarshalBinary(data []byte) error {
 
 func (ac *ArtCommand) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+8)
-	copy(data[0:8], ac.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], ac.OpCode)
-	data[10] = ac.ProtVerHi
-	data[11] = ac.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpCommand)
+	data[10] = 0
+	data[11] = 14
 	binary.BigEndian.PutUint16(data[12:14], ac.EstaMan)
 	dataLength := uint16(len(ac.Data))
 	if dataLength > 512 {
diff --git a/datarequest.go b/datarequest.go
index aeffab1..73e19d4 100644
--- a/datarequest.go
+++ b/datarequest.go
@@ -18,26 +18,14 @@ const (
 )
 
 type ArtDataRequest struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	EstaMan   uint16
-	Oem       uint16
-	Request   DataRequest
-	spare     [22]byte
+	EstaMan uint16
+	Oem     uint16
+	Request DataRequest
+	spare   [22]byte
 }
 
 func (adr *ArtDataRequest) GetOpCode() uint16 {
-	return adr.OpCode
-}
-
-func (adr *ArtDataRequest) GetProtVer() uint16 {
-	return uint16(adr.ProtVerHi)<<8 + uint16(adr.ProtVerLo)
-}
-
-func (adr *ArtDataRequest) GetID() [8]uint8 {
-	return adr.ID
+	return OpDataRequest
 }
 
 func (adr *ArtDataRequest) UnmarshalBinary(data []byte) error {
@@ -46,15 +34,14 @@ func (adr *ArtDataRequest) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtDataRequest packet must be at least 40 bytes long")
 	}
 
-	copy(adr.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], adr.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	adr.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	adr.ProtVerHi = data[10]
-	adr.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpDataRequest {
+		return errors.New("packet does not have the correct OpCode for an ArtDataRequest packet")
+	}
 
 	offset := 12
 	adr.EstaMan = binary.BigEndian.Uint16(data[offset : offset+2])
@@ -66,10 +53,10 @@ func (adr *ArtDataRequest) UnmarshalBinary(data []byte) error {
 
 func (adr *ArtDataRequest) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+32)
-	copy(data[0:8], adr.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], adr.OpCode)
-	data[10] = adr.ProtVerHi
-	data[11] = adr.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpDataRequest)
+	data[10] = 0
+	data[11] = 14
 	binary.BigEndian.PutUint16(data[12:14], adr.EstaMan)
 	binary.BigEndian.PutUint16(data[14:16], adr.Oem)
 	binary.BigEndian.PutUint16(data[16:18], uint16(adr.Request))
diff --git a/diagdata.go b/diagdata.go
index fe882fc..317fff5 100644
--- a/diagdata.go
+++ b/diagdata.go
@@ -17,10 +17,6 @@ const (
 )
 
 type ArtDiagData struct {
-	ID           [8]uint8
-	OpCode       uint16
-	ProtVerHi    uint8
-	ProtVerLo    uint8
 	filler1      uint8
 	DiagPriority DiagPriority
 	LogicalPort  uint8
@@ -29,19 +25,7 @@ type ArtDiagData struct {
 }
 
 func (add *ArtDiagData) GetOpCode() uint16 {
-	return add.OpCode
-}
-
-func (add *ArtDiagData) GetProtVer() uint16 {
-	return uint16(add.ProtVerHi)<<8 + uint16(add.ProtVerLo)
-}
-
-func (add *ArtDiagData) GetID() [8]uint8 {
-	return add.ID
-}
-
-func (add *ArtDiagData) Length() uint16 {
-	return uint16(len(add.Data))
+	return OpDiagData
 }
 
 func (add *ArtDiagData) UnmarshalBinary(data []byte) error {
@@ -50,15 +34,14 @@ func (add *ArtDiagData) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtDiagData packet must be at least 18 bytes long")
 	}
 
-	copy(add.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], add.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	add.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	add.ProtVerHi = data[10]
-	add.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpDiagData {
+		return errors.New("packet does not have the correct OpCode for an ArtDiagData packet")
+	}
 
 	offset := 12
 	add.filler1 = data[offset]
@@ -77,10 +60,10 @@ func (add *ArtDiagData) UnmarshalBinary(data []byte) error {
 
 func (add *ArtDiagData) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+10)
-	copy(data[0:8], add.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], add.OpCode)
-	data[10] = add.ProtVerHi
-	data[11] = add.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpDiagData)
+	data[10] = 0
+	data[11] = 14
 	data[12] = add.filler1
 	data[13] = uint8(add.DiagPriority)
 	data[14] = add.LogicalPort
diff --git a/dmx.go b/dmx.go
index 06a79d9..6b81d7d 100644
--- a/dmx.go
+++ b/dmx.go
@@ -7,31 +7,15 @@ import (
 )
 
 type ArtDmx struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	Sequence  uint8
-	Physical  uint8
-	SubUni    uint8
-	Net       uint8
-	Data      []uint8
+	Sequence uint8
+	Physical uint8
+	SubUni   uint8
+	Net      uint8
+	Data     []uint8
 }
 
 func (ad *ArtDmx) GetOpCode() uint16 {
-	return ad.OpCode
-}
-
-func (ad *ArtDmx) GetProtVer() uint16 {
-	return uint16(ad.ProtVerHi)<<8 + uint16(ad.ProtVerLo)
-}
-
-func (ad *ArtDmx) GetID() [8]uint8 {
-	return ad.ID
-}
-
-func (ad *ArtDmx) Length() uint16 {
-	return uint16(len(ad.Data))
+	return OpDmx
 }
 
 func (ad *ArtDmx) UnmarshalBinary(data []byte) error {
@@ -39,15 +23,14 @@ func (ad *ArtDmx) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtDmx packet must be at least 18 bytes long")
 	}
 
-	copy(ad.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], ad.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	ad.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	ad.ProtVerHi = data[10]
-	ad.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpDmx {
+		return errors.New("packet does not have the correct OpCode for an ArtDmx packet")
+	}
 
 	offset := 12
 
@@ -70,16 +53,17 @@ func (ad *ArtDmx) UnmarshalBinary(data []byte) error {
 }
 
 func (ad *ArtDmx) MarshalBinary() ([]byte, error) {
-	data := make([]byte, 8+10+ad.Length())
-	copy(data[0:8], ad.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], ad.OpCode)
-	data[10] = ad.ProtVerHi
-	data[11] = ad.ProtVerLo
+	// TODO(jwetzell): check max data length
+	data := make([]byte, 8+10+len(ad.Data))
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpDmx)
+	data[10] = 0
+	data[11] = 14
 	data[12] = ad.Sequence
 	data[13] = ad.Physical
 	data[14] = ad.SubUni
 	data[15] = ad.Net
-	binary.BigEndian.PutUint16(data[16:18], ad.Length())
+	binary.BigEndian.PutUint16(data[16:18], uint16(len(ad.Data)))
 	copy(data[18:], ad.Data)
 	return data, nil
 }
diff --git a/dmx_test.go b/dmx_test.go
index 3aa1c4b..4bd0f74 100644
--- a/dmx_test.go
+++ b/dmx_test.go
@@ -17,45 +17,33 @@ func TestGoodArtDmx(t *testing.T) {
 			Name: "512 All Zeroes",
 			Data: []byte{65, 114, 116, 45, 78, 101, 116, 0, 0, 80, 0, 14, 237, 0, 1, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
 			Expected: &artnet.ArtDmx{
-				ID:        [8]byte{'A', 'r', 't', '-', 'N', 'e', 't', 0x00},
-				OpCode:    artnet.OpDmx,
-				ProtVerHi: 0,
-				ProtVerLo: 14,
-				Sequence:  237,
-				Physical:  0,
-				SubUni:    1,
-				Net:       0,
-				Data:      make([]uint8, 512),
+				Sequence: 237,
+				Physical: 0,
+				SubUni:   1,
+				Net:      0,
+				Data:     make([]uint8, 512),
 			},
 		},
 		{
 			Name: "ACT Packet 1",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x50, 0x00, 0x0e, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtDmx{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpDmx,
-				ProtVerHi: 0,
-				ProtVerLo: 14,
-				Sequence:  0,
-				Physical:  0,
-				SubUni:    1,
-				Net:       0,
-				Data:      make([]uint8, 512),
+				Sequence: 0,
+				Physical: 0,
+				SubUni:   1,
+				Net:      0,
+				Data:     make([]uint8, 512),
 			},
 		},
 		{
 			Name: "ACT Packet 2",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x50, 0x00, 0x0e, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0xff, 0x7f, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtDmx{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpDmx,
-				ProtVerHi: 0,
-				ProtVerLo: 14,
-				Sequence:  0,
-				Physical:  0,
-				SubUni:    1,
-				Net:       0,
-				Data:      append([]uint8{0xff, 0x7f}, make([]uint8, 510)...),
+				Sequence: 0,
+				Physical: 0,
+				SubUni:   1,
+				Net:      0,
+				Data:     append([]uint8{0xff, 0x7f}, make([]uint8, 510)...),
 			},
 		},
 	}
@@ -69,22 +57,6 @@ func TestGoodArtDmx(t *testing.T) {
 			t.Fatalf("failed to decode ArtDmx: %s", err)
 		}
 
-		if got.OpCode != test.Expected.OpCode {
-			t.Fatalf("ArtDmx OpCode does not match got: %d expected: %d", got.OpCode, test.Expected.OpCode)
-		}
-
-		if !slices.Equal(got.ID[:], test.Expected.ID[:]) {
-			t.Fatalf("ArtDmx ID does not match got: %+v expected: %+v", got.ID, test.Expected.ID)
-		}
-
-		if got.ProtVerHi != test.Expected.ProtVerHi {
-			t.Fatalf("ArtDmx ProtVerHi does not match got: %d expected: %d", got.ProtVerHi, test.Expected.ProtVerHi)
-		}
-
-		if got.ProtVerLo != test.Expected.ProtVerLo {
-			t.Fatalf("ArtDmx ProtVerLo does not match got: %d expected: %d", got.ProtVerLo, test.Expected.ProtVerLo)
-		}
-
 		if got.Sequence != test.Expected.Sequence {
 			t.Fatalf("ArtDmx Sequence does not match got: %d expected: %d", got.Sequence, test.Expected.Sequence)
 		}
@@ -101,10 +73,6 @@ func TestGoodArtDmx(t *testing.T) {
 			t.Fatalf("ArtDmx Net does not match got: %d expected: %d", got.Net, test.Expected.Net)
 		}
 
-		if got.Length() != test.Expected.Length() {
-			t.Fatalf("ArtDmx Length does not match got: %d expected: %d", got.Length(), test.Expected.Length())
-		}
-
 		if !slices.Equal(got.Data, test.Expected.Data) {
 			t.Fatalf("ArtDmx Data does not match got: %+v expected: %+v", got.Data, test.Expected.Data)
 		}
@@ -127,15 +95,11 @@ func BenchmarkArtDmxUnmarshalBinary(b *testing.B) {
 
 func BenchmarkArtDmxMarshalBinary(b *testing.B) {
 	data := artnet.ArtDmx{
-		ID:        [8]byte{'A', 'r', 't', '-', 'N', 'e', 't', 0x00},
-		OpCode:    artnet.OpDmx,
-		ProtVerHi: 0,
-		ProtVerLo: 14,
-		Sequence:  237,
-		Physical:  0,
-		SubUni:    1,
-		Net:       0,
-		Data:      make([]uint8, 512),
+		Sequence: 237,
+		Physical: 0,
+		SubUni:   1,
+		Net:      0,
+		Data:     make([]uint8, 512),
 	}
 
 	for b.Loop() {
diff --git a/ipprog.go b/ipprog.go
index 2ac40b8..cff1526 100644
--- a/ipprog.go
+++ b/ipprog.go
@@ -7,10 +7,6 @@ import (
 )
 
 type ArtIpProg struct {
-	ID         [8]uint8
-	OpCode     uint16
-	ProtVerHi  uint8
-	ProtVerLo  uint8
 	filler1    uint8
 	filler2    uint8
 	Command    uint8
@@ -36,15 +32,7 @@ type ArtIpProg struct {
 }
 
 func (aip *ArtIpProg) GetOpCode() uint16 {
-	return aip.OpCode
-}
-
-func (aip *ArtIpProg) GetProtVer() uint16 {
-	return uint16(aip.ProtVerHi)<<8 + uint16(aip.ProtVerLo)
-}
-
-func (aip *ArtIpProg) GetID() [8]uint8 {
-	return aip.ID
+	return OpIpProg
 }
 
 func (aip *ArtIpProg) UnmarshalBinary(data []byte) error {
@@ -52,15 +40,14 @@ func (aip *ArtIpProg) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtIpProg packet must be at least 18 bytes long")
 	}
 
-	copy(aip.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], aip.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	aip.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	aip.ProtVerHi = data[10]
-	aip.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpIpProg {
+		return errors.New("packet does not have the correct OpCode for an ArtIpProg packet")
+	}
 
 	offset := 12
 
@@ -97,10 +84,10 @@ func (aip *ArtIpProg) UnmarshalBinary(data []byte) error {
 
 func (aip *ArtIpProg) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+26)
-	copy(data[0:8], aip.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], aip.OpCode)
-	data[10] = aip.ProtVerHi
-	data[11] = aip.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpIpProg)
+	data[10] = 0
+	data[11] = 14
 	data[12] = aip.filler1
 	data[13] = aip.filler2
 	data[14] = aip.Command
diff --git a/ipprog_test.go b/ipprog_test.go
index 238f178..678f881 100644
--- a/ipprog_test.go
+++ b/ipprog_test.go
@@ -17,10 +17,6 @@ func TestGoodArtIpProgUnmarshal(t *testing.T) {
 			Name: "ACT Packet 1",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0xf8, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtIpProg{
-				ID:         artnet.ArtNetID,
-				OpCode:     artnet.OpIpProg,
-				ProtVerHi:  0x00,
-				ProtVerLo:  0x0e,
 				Command:    0x00,
 				ProgIpHi:   0x00,
 				ProgIp2:    0x00,
diff --git a/ipprogreply.go b/ipprogreply.go
index 57ac765..84dc810 100644
--- a/ipprogreply.go
+++ b/ipprogreply.go
@@ -7,10 +7,6 @@ import (
 )
 
 type ArtIpProgReply struct {
-	ID         [8]uint8
-	OpCode     uint16
-	ProtVerHi  uint8
-	ProtVerLo  uint8
 	filler1    uint8
 	filler2    uint8
 	filler3    uint8
@@ -36,15 +32,7 @@ type ArtIpProgReply struct {
 }
 
 func (aipr *ArtIpProgReply) GetOpCode() uint16 {
-	return aipr.OpCode
-}
-
-func (aipr *ArtIpProgReply) GetProtVer() uint16 {
-	return uint16(aipr.ProtVerHi)<<8 + uint16(aipr.ProtVerLo)
-}
-
-func (aipr *ArtIpProgReply) GetID() [8]uint8 {
-	return aipr.ID
+	return OpIpProgReply
 }
 
 func (aipr *ArtIpProgReply) UnmarshalBinary(data []byte) error {
@@ -52,15 +40,14 @@ func (aipr *ArtIpProgReply) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtIpProgReply packet must be at least 18 bytes long")
 	}
 
-	copy(aipr.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], aipr.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	aipr.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	aipr.ProtVerHi = data[10]
-	aipr.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpIpProgReply {
+		return errors.New("packet does not have the correct OpCode for an ArtIpProgReply packet")
+	}
 
 	offset := 12
 
@@ -98,10 +85,10 @@ func (aipr *ArtIpProgReply) UnmarshalBinary(data []byte) error {
 
 func (aipr *ArtIpProgReply) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+26)
-	copy(data[0:8], aipr.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], aipr.OpCode)
-	data[10] = aipr.ProtVerHi
-	data[11] = aipr.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpIpProgReply)
+	data[10] = 0
+	data[11] = 14
 	data[12] = aipr.filler1
 	data[13] = aipr.filler2
 	data[14] = aipr.filler3
diff --git a/nzs.go b/nzs.go
index e6262b4..2b0423b 100644
--- a/nzs.go
+++ b/nzs.go
@@ -7,10 +7,6 @@ import (
 )
 
 type ArtNzs struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
 	Sequence  uint8
 	StartCode uint8
 	SubUni    uint8
@@ -19,19 +15,7 @@ type ArtNzs struct {
 }
 
 func (an *ArtNzs) GetOpCode() uint16 {
-	return an.OpCode
-}
-
-func (an *ArtNzs) GetProtVer() uint16 {
-	return uint16(an.ProtVerHi)<<8 + uint16(an.ProtVerLo)
-}
-
-func (an *ArtNzs) GetID() [8]uint8 {
-	return an.ID
-}
-
-func (an *ArtNzs) Length() uint16 {
-	return uint16(len(an.Data))
+	return OpNzs
 }
 
 func (an *ArtNzs) UnmarshalBinary(data []byte) error {
@@ -40,15 +24,14 @@ func (an *ArtNzs) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtNzs packet must be at least 18 bytes long")
 	}
 
-	copy(an.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], an.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	an.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	an.ProtVerHi = data[10]
-	an.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpNzs {
+		return errors.New("packet does not have the correct OpCode for an ArtNzs packet")
+	}
 
 	offset := 12
 	an.Sequence = data[offset]
@@ -68,10 +51,10 @@ func (an *ArtNzs) UnmarshalBinary(data []byte) error {
 
 func (an *ArtNzs) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+8)
-	copy(data[0:8], an.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], an.OpCode)
-	data[10] = an.ProtVerHi
-	data[11] = an.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpNzs)
+	data[10] = 0
+	data[11] = 14
 	data[12] = an.Sequence
 	data[13] = an.StartCode
 	data[14] = an.SubUni
diff --git a/packet.go b/packet.go
index b648b6e..fa958ad 100644
--- a/packet.go
+++ b/packet.go
@@ -8,5 +8,4 @@ type ArtNetPacket interface {
 	encoding.BinaryUnmarshaler
 	encoding.BinaryMarshaler
 	GetOpCode() uint16
-	GetID() [8]uint8
 }
diff --git a/poll.go b/poll.go
index 71f8c13..f99b1e1 100644
--- a/poll.go
+++ b/poll.go
@@ -7,10 +7,6 @@ import (
 )
 
 type ArtPoll struct {
-	ID           [8]uint8
-	OpCode       uint16
-	ProtVerHi    uint8
-	ProtVerLo    uint8
 	Flags        uint8
 	DiagPriority uint8
 	// TODO(jwetzell): support extended poll fields
@@ -21,15 +17,7 @@ type ArtPoll struct {
 }
 
 func (ap *ArtPoll) GetOpCode() uint16 {
-	return ap.OpCode
-}
-
-func (ap *ArtPoll) GetProtVer() uint16 {
-	return uint16(ap.ProtVerHi)<<8 + uint16(ap.ProtVerLo)
-}
-
-func (ap *ArtPoll) GetID() [8]uint8 {
-	return ap.ID
+	return OpPoll
 }
 
 func (ap *ArtPoll) UnmarshalBinary(data []byte) error {
@@ -38,15 +26,14 @@ func (ap *ArtPoll) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtPoll packet must be at least 14 bytes long")
 	}
 
-	copy(ap.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], ap.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	ap.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	ap.ProtVerHi = data[10]
-	ap.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpPoll {
+		return errors.New("packet does not have the correct OpCode for an ArtPoll packet")
+	}
 
 	offset := 12
 	ap.Flags = data[offset]
@@ -69,10 +56,10 @@ func (ap *ArtPoll) UnmarshalBinary(data []byte) error {
 
 func (ap *ArtPoll) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+14)
-	copy(data[0:8], ap.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], ap.OpCode)
-	data[10] = ap.ProtVerHi
-	data[11] = ap.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpPoll)
+	data[10] = 0
+	data[11] = 14
 	data[12] = ap.Flags
 	data[13] = ap.DiagPriority
 	binary.BigEndian.PutUint16(data[14:16], ap.TargetPortAddressTop)
diff --git a/poll_test.go b/poll_test.go
index 52b850b..e629a3a 100644
--- a/poll_test.go
+++ b/poll_test.go
@@ -17,170 +17,185 @@ func TestGoodArtPollUnmarshal(t *testing.T) {
 			Name: "ACT Packet 1",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:        0x00,
+				DiagPriority: 0x00,
 			},
 		},
 		{
 			Name: "ACT Packet 2",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:        0x00,
+				DiagPriority: 0x00,
 			},
 		},
 		{
 			Name: "ACT Packet 3",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                0x00,
+				DiagPriority:         0x00,
+				TargetPortAddressTop: 0x7fff,
 			},
 		},
 		{
 			Name: "ACT Packet 4",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                0x00,
+				DiagPriority:         0x00,
+				TargetPortAddressTop: 0x7fff,
 			},
 		},
 		{
 			Name: "ACT Packet 5",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x00,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
 			},
 		},
 		{
 			Name: "ACT Packet 6",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x00,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
 			},
 		},
 		{
 			Name: "ACT Packet 7",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x00,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
+				EstaMan:                 0x5379,
 			},
 		},
 		{
 			Name: "ACT Packet 8",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x00,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
+				EstaMan:                 0x5379,
 			},
 		},
 		{
 			Name: "ACT Packet 9",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 10",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 11",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 12",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 13",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 14",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 15",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-			},
-		},
-		{
-			Name: "ACT Packet 16",
-			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x21, 0x0a, 0x00, 0x00, 0x3e, 0x36, 0x19, 0x07, 0x33, 0x00, 0x06, 0x22, 0x69, 0x00, 0x00, 0x79, 0x53, 0x41, 0x43, 0x54, 0x2e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0x43, 0x54, 0x2e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
-			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x00,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
+				EstaMan:                 0x5379,
+				Oem:                     0x2269,
 			},
 		},
+		// TODO(jwetzell): uncomment when extend field parsing is done
+		// {
+		// 	Name: "ACT Packet 10",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 11",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 12",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 13",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 14",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 15",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
+		// {
+		// 	Name: "ACT Packet 16",
+		// 	Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x00, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x21, 0x0a, 0x00, 0x00, 0x3e, 0x36, 0x19, 0x07, 0x33, 0x00, 0x06, 0x22, 0x69, 0x00, 0x00, 0x79, 0x53, 0x41, 0x43, 0x54, 0x2e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0x43, 0x54, 0x2e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
+		// 	Expected: &artnet.ArtPoll{
+		// 		Flags:                   0x00,
+		// 		DiagPriority:            0x00,
+		// 		TargetPortAddressTop:    0x7fff,
+		// 		TargetPortAddressBottom: 0x0000,
+		// 		EstaMan:                 0x5379,
+		// 		Oem:                     0x2269,
+		// 	},
+		// },
 		{
 			Name: "ACT Packet 17",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x20, 0x00, 0x0e, 0x06, 0x00, 0x7f, 0xff, 0x00, 0x00, 0x53, 0x79, 0x22, 0x69},
 			Expected: &artnet.ArtPoll{
-				ID:        artnet.ArtNetID,
-				OpCode:    0x2000,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
+				Flags:                   0x06,
+				DiagPriority:            0x00,
+				TargetPortAddressTop:    0x7fff,
+				TargetPortAddressBottom: 0x0000,
+				EstaMan:                 0x5379,
+				Oem:                     0x2269,
 			},
 		},
 	}
diff --git a/pollreply.go b/pollreply.go
index 0c84a58..559bf28 100644
--- a/pollreply.go
+++ b/pollreply.go
@@ -7,8 +7,6 @@ import (
 )
 
 type ArtPollReply struct {
-	ID          [8]uint8
-	OpCode      uint16
 	IPAddress   [4]uint8
 	Port        uint16
 	VersInfo    uint16
@@ -49,11 +47,7 @@ type ArtPollReply struct {
 }
 
 func (ap *ArtPollReply) GetOpCode() uint16 {
-	return ap.OpCode
-}
-
-func (ap *ArtPollReply) GetID() [8]uint8 {
-	return ap.ID
+	return OpPollReply
 }
 
 func (ap *ArtPollReply) UnmarshalBinary(data []byte) error {
@@ -62,13 +56,15 @@ func (ap *ArtPollReply) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtPollReply packet must be at least 207 bytes long")
 	}
 
-	copy(ap.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], ap.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	ap.OpCode = binary.LittleEndian.Uint16(data[8:10])
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpPollReply {
+		return errors.New("packet does not have the correct OpCode for an ArtPollReply packet")
+	}
+
 	ap.IPAddress[0] = data[10]
 	ap.IPAddress[1] = data[11]
 	ap.IPAddress[2] = data[12]
@@ -106,8 +102,8 @@ func (ap *ArtPollReply) MarshalBinary() ([]byte, error) {
 		return nil, errors.New("DefaultRespUID must not be greater than 281474976710655")
 	}
 	data := make([]byte, 8+230)
-	copy(data[0:8], ap.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], ap.OpCode)
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpPollReply)
 	data[10] = ap.IPAddress[0]
 	data[11] = ap.IPAddress[1]
 	data[12] = ap.IPAddress[2]
diff --git a/sync.go b/sync.go
index bc86866..149ba8f 100644
--- a/sync.go
+++ b/sync.go
@@ -7,24 +7,12 @@ import (
 )
 
 type ArtSync struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	Aux1      uint8
-	Aux2      uint8
+	Aux1 uint8
+	Aux2 uint8
 }
 
 func (as *ArtSync) GetOpCode() uint16 {
-	return as.OpCode
-}
-
-func (as *ArtSync) GetProtVer() uint16 {
-	return uint16(as.ProtVerHi)<<8 + uint16(as.ProtVerLo)
-}
-
-func (as *ArtSync) GetID() [8]uint8 {
-	return as.ID
+	return OpSync
 }
 
 func (as *ArtSync) UnmarshalBinary(data []byte) error {
@@ -33,15 +21,14 @@ func (as *ArtSync) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtSync packet must be at least 14 bytes long")
 	}
 
-	copy(as.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], as.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	as.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	as.ProtVerHi = data[10]
-	as.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpSync {
+		return errors.New("packet does not have the correct OpCode for an ArtSync packet")
+	}
 
 	offset := 12
 	as.Aux1 = data[offset]
@@ -51,10 +38,10 @@ func (as *ArtSync) UnmarshalBinary(data []byte) error {
 
 func (as *ArtSync) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+6)
-	copy(data[0:8], as.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], as.OpCode)
-	data[10] = as.ProtVerHi
-	data[11] = as.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpSync)
+	data[10] = 0
+	data[11] = 14
 	data[12] = as.Aux1
 	data[13] = as.Aux2
 	return data, nil
diff --git a/timecode.go b/timecode.go
index 5bf0481..e2cc13b 100644
--- a/timecode.go
+++ b/timecode.go
@@ -7,29 +7,17 @@ import (
 )
 
 type ArtTimeCode struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	Filler1   uint8
-	StreamId  uint8
-	Frames    uint8
-	Seconds   uint8
-	Minutes   uint8
-	Hours     uint8
-	Type      uint8
+	filler1  uint8
+	StreamId uint8
+	Frames   uint8
+	Seconds  uint8
+	Minutes  uint8
+	Hours    uint8
+	Type     uint8
 }
 
 func (atc *ArtTimeCode) GetOpCode() uint16 {
-	return atc.OpCode
-}
-
-func (atc *ArtTimeCode) GetProtVer() uint16 {
-	return uint16(atc.ProtVerHi)<<8 + uint16(atc.ProtVerLo)
-}
-
-func (atc *ArtTimeCode) GetID() [8]uint8 {
-	return atc.ID
+	return OpTimeCode
 }
 
 func (atc *ArtTimeCode) UnmarshalBinary(data []byte) error {
@@ -37,18 +25,17 @@ func (atc *ArtTimeCode) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtTimeCode packet must be at least 14 bytes long")
 	}
 
-	copy(atc.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], atc.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	atc.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	atc.ProtVerHi = data[10]
-	atc.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpTimeCode {
+		return errors.New("packet does not have the correct OpCode for an ArtTimeCode packet")
+	}
 
 	offset := 12
-	atc.Filler1 = data[offset]
+	atc.filler1 = data[offset]
 	atc.StreamId = data[offset+1]
 	atc.Frames = data[offset+2]
 	atc.Seconds = data[offset+3]
@@ -60,12 +47,12 @@ func (atc *ArtTimeCode) UnmarshalBinary(data []byte) error {
 
 func (atc *ArtTimeCode) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+11)
-	copy(data[0:8], atc.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], atc.OpCode)
-	data[10] = atc.ProtVerHi
-	data[11] = atc.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpTimeCode)
+	data[10] = 0
+	data[11] = 14
 	offset := 12
-	data[offset] = atc.Filler1
+	data[offset] = atc.filler1
 	data[offset+1] = atc.StreamId
 	data[offset+2] = atc.Frames
 	data[offset+3] = atc.Seconds
diff --git a/timecode_test.go b/timecode_test.go
index 2452caa..2e5aabd 100644
--- a/timecode_test.go
+++ b/timecode_test.go
@@ -17,17 +17,12 @@ func TestGoodArtTimeCodeUnmarshal(t *testing.T) {
 			Name: "Basic timecode",
 			Data: []byte{65, 114, 116, 45, 78, 101, 116, 0, 0, 151, 0, 14, 0, 0, 11, 17, 3, 0, 0},
 			Expected: &artnet.ArtTimeCode{
-				ID:        [8]uint8{'A', 'r', 't', '-', 'N', 'e', 't', 0x00},
-				OpCode:    artnet.OpTimeCode,
-				ProtVerHi: 0,
-				ProtVerLo: 14,
-				Filler1:   0,
-				StreamId:  0,
-				Frames:    11,
-				Seconds:   17,
-				Minutes:   3,
-				Hours:     0,
-				Type:      0,
+				StreamId: 0,
+				Frames:   11,
+				Seconds:  17,
+				Minutes:  3,
+				Hours:    0,
+				Type:     0,
 			},
 		},
 	}
@@ -63,17 +58,12 @@ func BenchmarkArtTimeCodeUnmarshalBinary(b *testing.B) {
 
 func BenchmarkArtTimeCodeMarshalBinary(b *testing.B) {
 	data := artnet.ArtTimeCode{
-		ID:        [8]uint8{'A', 'r', 't', '-', 'N', 'e', 't', 0x00},
-		OpCode:    artnet.OpTimeCode,
-		ProtVerHi: 0,
-		ProtVerLo: 14,
-		Filler1:   0,
-		StreamId:  0,
-		Frames:    11,
-		Seconds:   17,
-		Minutes:   3,
-		Hours:     0,
-		Type:      0,
+		StreamId: 0,
+		Frames:   11,
+		Seconds:  17,
+		Minutes:  3,
+		Hours:    0,
+		Type:     0,
 	}
 
 	for b.Loop() {
diff --git a/todrequest.go b/todrequest.go
index 6dd92d5..89f33d5 100644
--- a/todrequest.go
+++ b/todrequest.go
@@ -13,34 +13,22 @@ const (
 )
 
 type ArtTodRequest struct {
-	ID        [8]uint8
-	OpCode    uint16
-	ProtVerHi uint8
-	ProtVerLo uint8
-	filler1   uint8
-	filler2   uint8
-	spare1    uint8
-	spare2    uint8
-	spare3    uint8
-	spare4    uint8
-	spare5    uint8
-	spare6    uint8
-	spare7    uint8
-	Net       uint8
-	Command   TodRequestCommand
-	Address   []uint8
+	filler1 uint8
+	filler2 uint8
+	spare1  uint8
+	spare2  uint8
+	spare3  uint8
+	spare4  uint8
+	spare5  uint8
+	spare6  uint8
+	spare7  uint8
+	Net     uint8
+	Command TodRequestCommand
+	Address []uint8
 }
 
 func (adr *ArtTodRequest) GetOpCode() uint16 {
-	return adr.OpCode
-}
-
-func (adr *ArtTodRequest) GetProtVer() uint16 {
-	return uint16(adr.ProtVerHi)<<8 + uint16(adr.ProtVerLo)
-}
-
-func (adr *ArtTodRequest) GetID() [8]uint8 {
-	return adr.ID
+	return OpTodRequest
 }
 
 func (adr *ArtTodRequest) UnmarshalBinary(data []byte) error {
@@ -49,15 +37,14 @@ func (adr *ArtTodRequest) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtTodRequest packet must be at least 32 bytes long")
 	}
 
-	copy(adr.ID[:], data[0:8])
-
-	if !slices.Equal(ArtNetID[:], adr.ID[:]) {
+	if !slices.Equal(ArtNetID[:], data[0:8]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	adr.OpCode = binary.LittleEndian.Uint16(data[8:10])
-	adr.ProtVerHi = data[10]
-	adr.ProtVerLo = data[11]
+	opCode := binary.LittleEndian.Uint16(data[8:10])
+	if opCode != OpTodRequest {
+		return errors.New("packet does not have the correct OpCode for an ArtTodRequest packet")
+	}
 
 	offset := 12
 	adr.filler1 = data[offset]
@@ -85,10 +72,10 @@ func (adr *ArtTodRequest) MarshalBinary() ([]byte, error) {
 		return nil, errors.New("address count must not be greater than 32")
 	}
 	data := make([]byte, 8+16+len(adr.Address))
-	copy(data[0:8], adr.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], adr.OpCode)
-	data[10] = adr.ProtVerHi
-	data[11] = adr.ProtVerLo
+	copy(data[0:8], ArtNetID[:])
+	binary.LittleEndian.PutUint16(data[8:10], OpTodRequest)
+	data[10] = 0
+	data[11] = 14
 	data[12] = adr.filler1
 	data[13] = adr.filler2
 	data[14] = adr.spare1
diff --git a/todrequest_test.go b/todrequest_test.go
index 3e999c1..3a0eb74 100644
--- a/todrequest_test.go
+++ b/todrequest_test.go
@@ -17,234 +17,162 @@ func TestGoodArtTodRequestUnmarshal(t *testing.T) {
 			Name: "ACT Packet 1",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x00},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x00},
 			},
 		},
 		{
 			Name: "ACT Packet 2",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 3",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 4",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 5",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 6",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 7",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 8",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 9",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 10",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 11",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 12",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 13",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 14",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 15",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 16",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 17",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 		{
 			Name: "ACT Packet 18",
 			Data: []byte{0x41, 0x72, 0x74, 0x2d, 0x4e, 0x65, 0x74, 0x00, 0x00, 0x80, 0x00, 0x0e, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
 			Expected: &artnet.ArtTodRequest{
-				ID:        artnet.ArtNetID,
-				OpCode:    artnet.OpTodRequest,
-				ProtVerHi: 0x00,
-				ProtVerLo: 0x0e,
-				Command:   artnet.TodFull,
-				Net:       0x00,
-				Address:   []uint8{0x10},
+				Command: artnet.TodFull,
+				Net:     0x00,
+				Address: []uint8{0x10},
 			},
 		},
 	}
diff --git a/trigger.go b/trigger.go
index d2da50a..172a9c4 100644
--- a/trigger.go
+++ b/trigger.go
@@ -16,8 +16,8 @@ const (
 )
 
 type ArtTrigger struct {
-	ID        [8]uint8
-	OpCode    uint16
+	id        [8]uint8
+	opCode    uint16
 	ProtVerHi uint8
 	ProtVerLo uint8
 	filler1   uint8
@@ -29,15 +29,7 @@ type ArtTrigger struct {
 }
 
 func (at *ArtTrigger) GetOpCode() uint16 {
-	return at.OpCode
-}
-
-func (at *ArtTrigger) GetProtVer() uint16 {
-	return uint16(at.ProtVerHi)<<8 + uint16(at.ProtVerLo)
-}
-
-func (at *ArtTrigger) GetID() [8]uint8 {
-	return at.ID
+	return OpTrigger
 }
 
 func (at *ArtTrigger) UnmarshalBinary(data []byte) error {
@@ -46,13 +38,16 @@ func (at *ArtTrigger) UnmarshalBinary(data []byte) error {
 		return errors.New("ArtTrigger packet must be at least 18 bytes long")
 	}
 
-	copy(at.ID[:], data[0:8])
+	copy(at.id[:], data[0:8])
 
-	if !slices.Equal(ArtNetID[:], at.ID[:]) {
+	if !slices.Equal(ArtNetID[:], at.id[:]) {
 		return errors.New("ID does not match Art-Net ID")
 	}
 
-	at.OpCode = binary.LittleEndian.Uint16(data[8:10])
+	at.opCode = binary.LittleEndian.Uint16(data[8:10])
+	if at.opCode != OpTrigger {
+		return errors.New("packet does not have the correct OpCode for an ArtTrigger packet")
+	}
 	at.ProtVerHi = data[10]
 	at.ProtVerLo = data[11]
 
@@ -69,8 +64,8 @@ func (at *ArtTrigger) UnmarshalBinary(data []byte) error {
 
 func (at *ArtTrigger) MarshalBinary() ([]byte, error) {
 	data := make([]byte, 8+10)
-	copy(data[0:8], at.ID[:])
-	binary.LittleEndian.PutUint16(data[8:10], at.OpCode)
+	copy(data[0:8], at.id[:])
+	binary.LittleEndian.PutUint16(data[8:10], at.opCode)
 	data[10] = at.ProtVerHi
 	data[11] = at.ProtVerLo
 	data[12] = at.filler1