Chasing a problem in an AD2437 system where a bus powered subnode is failing to be discovered (never responds to discovery packets) but works fine when locally powered.
In the network settings I would have guessed that Discovery Start Delay field would change the delay from when the B port turns on bus power to when it starts the discovery probing.
The official explanation is a little nebulous to me, what does it mean by "reset" when trying to discover the next node? https://wiki.analog.com/resources/tools-software/a2bv2/a2bssplususerguide/networkproperties
Is this trying to say there's only a delay for "discovering" the main node?
Putting a scope probe on the B port A2B signals it seems probing always starts a few msec after bus power is enabled and always runs for 100 msec before stopping. Here's a typical example (LVDS signal not visible at this scale but I have other captures of that).
I wanted to give the sub node more time on the off chance that the node power isn't stable yet or the AD2437 is for some reason waking up very slowly.
Questions:
- What is Discovery Start Delay actually controlling?
- Is it possible to increase the discovery time (i.e.bus power on and probing, currently around 100 msec) from inside of SS+?
Not relevant to my question but the reason I'm looking at this: This system worked fine in early January and was not powered up again until the other day. I believe since it last ran I applied update 2 to SS+ 2.3.0. However I can't see how that update would have changed the A2B SS+ plugin. I had also kept SS+ 2.2.0 around and that fails too. The error is discovery timeout and I can see the sub node is not sending back the upstream (i.e. from its port A) response packet when bus powered, but it sending it when locally powered.
Something must have changed but so far I haven't figured out what,. There's no visibility in to what the subnode state actually is so it makes debug a bunch of random guesses, and one of those random guesses was going to be to leave the bus power on for longer.
TIA for any insight/advice.
Brewster
