Does controller need it's UID and support any PIDs?

[hamish]

It's responders that respond, not the controller.
It may be that your controller is behaving as a responder.
Responders will respond with ACK_TIMER if they require additional time
to process the response.

Originally Posted by alvangee

Probably it's a noob question, but couldn't find any mentions on this topic.
There's a list of required parameters and a whole lot of discussions on how responders should operate.

But if it's a controller, is it required that it has it's own UID, responds to Discovery commands and supports any of the PIDs?

Now I have Enttec MK2 controllers and I can see that they respond to Discovery with their own UID, but to any other PID request they send ACK_TIMER. Not sure why ACK_TIMER though, it seems more appropriate to send NACK with the reason NR_UNKNOW_PID to tell that PID is not supported.

[alvangee]

Originally Posted by hamish

Responders will respond with ACK_TIMER if they require additional time
to process the response.

Exactly. That's why I'm surprised with ACK_TIMER from controller. And it's not in "responder" mode.

It's responders that respond, not controllers

Does this mean that controller doesn't have to have it's own UID and respond even to Discovery requests?

[hamish]

A controller has it's own UID, used in all commands to responders. Responses to the controller are addressed to the controller by it's UID.

There's nothing, that I'm aware of in the standard, to prevent a controller acting as a responder on receipt of a command.