ACT_TIMER to Set messages

[sblair]

If you look at the middle of Section 6.3.3 I believe it addresses this:

When the responder is able to provide the required information, it shall add the correctly formatted GET_COMMAND_RESPONSE message or SET_COMMAND_RESPONSE message to its QUEUED_MESSAGE list. It shall also increment its Message Count at the time the message is added to the QUEUED_MESSAGE list.

So if you did an ACK_TIMER for the SET operation then when it is complete you should queue a SET_COMMAND_RESPONSE. A GET_COMMAND_RESPONSE can be queued to show that the value was changed locally. So if someone changes the DMX Address via the front panel then the GET_COMMAND_RESPONSE can be queued to show the new value.

For Transaction Number see this in Section 6.2.6:

Controller generated packets increment this field every time an RDM packet is transmitted.

So the transaction number gets incremented with each message the CONTROLLER sends out. It is not for the full target operation but for each packet that is sent.