ArtTimeCode
The ArtTimeCode packet is used to send Time Code to the network. There is no reply packet.
Broadcast and Unicast algorithms
The ArtTimeCode packet can be broadcast or unicast to the network. The decision on which to use is very much application specific. The most common implementation involves a single controller broadcasting to all other devices.
In some circumstances a controller may need the networks devices to be synchronised but with offset times. In this instance, the controller will unicast ArtTimeCode to the network devices.
ArtTimeCode – Packet Definition
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 ArtTimeCode packet this field is set to ‘OpTimeCode’.
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.
Filler1-2
These fields are used to pad the length of this packet to match the ArtPoll header. They are transmitted as zero and never tested by receivers.
Frames
The Frames field is an 8-bit number that defines the number of frames encoded in the time. The value ranges from 010 to 2910, although not all values are legal for all types of time code. See table below.
Seconds
The Seconds field is an 8-bit number that defines the number of seconds encoded in the time. The value ranges from 010 to 5910.
Minutes
The Minutes field is an 8-bit number that defines the number of minutes encoded in the time. The value ranges from 010 to 5910.
Hours
The Hours field is an 8-bit number that defines the number of hours encoded in the time. The value ranges from 010 to 2310.
Type
The Type field is an 8-bit number that defines the time base of the encoded time. The following table describes the options:
