ArtPoll

ArtPoll

For an introduction to ArtPoll and ArtPollReply, please refer to Discovery Packets.

ArtPoll – Packet Definition

Byte Offset Name Size Brief Description
0 ID[] 8 String which Identifies this as Art-Net
8 OpCodeLo 1 Defines this packet type
9 OpCodeHi 1 Defines this packet type
10 ProtVerHi 1 Protocol Version
11 ProtVerLo 1 Protocol Version
12 TalkToMe 1 Configuration bits
13 Priority 1 Diagnostics priority

 

ID

The ID field is 8 bytes in length and contains the null terminated string of ASCII characters:

A r t – N e t

The purpose of the field is to identify the packet as an Art-Net protocol packet. All Art-Net packets start with this field. Receivers must check this field is correct and discard the packet if it is not.

OpCode

The OpCode field is a 16-bit word transmitted low byte first. The OpCode identifies the packet type. In the ArtPoll packet this field is set to ‘OpPoll’.

ProtVer

The ProtVer field is a 16-bit word transmitted high byte first. It identifies the version of the Art-Net protocol. The protocol version is not related to Art-Net 1, II, 3 or 4. Only one protocol version has ever existed in production equipment which is 1410. Receivers should use the following good packet test:

ProtVer >= 14

The ProtVer may be increased in a future releases to identify significant functionality changes.

TalkToMe

The TalkToMe field is a single byte encoded as bit fields. The bit fields all control basic protocol behaviour of the node that receives the packet. The following table defines the fields.

 bit table1

 

 

 

 

 

 

 

 

 

 

 

 

 

Priority

The Priority field is one byte in length and specifies the minimum priority of diagnostics message that the controller wishes to receive. This field can be ignored if diagnostics messages are disabled in TalkToMe->2.