State machine silent after USB interaction

George

Howdy Josh,

I've got a weird issue.

Session running fine.
Some sort of USB interaction (e.g. plugging something in, opening a connection) during a trial (Trial 1).
That trial (Trial 1) and the following trial (Trial 2) complete successfully.
Trial (Trial 3) is initiated by Matlab and state machine runs it, but communication between state machine and Matlab is lost, Matlab hangs.

I can tell the state machine runs Trial 3 because I hear the valve clicking at the correct time. I can tell "communication is lost" because the Console doesn't update but also I added a message into RunStateMachine for when a NewMessage is received and it just stops after the state matrix is sent. Ctrl+C doesn't work even though Matlab hasn't crashed, which means it's not hung in RunStateMachine but in a MEX file?

I can cause the issue reliably by powering on some hardware that has a USB connection to the computer while a trial is running. It's got something to do with the USB stream for the Rotary Encoder Module, as other protocols that don't use it don't have this problem. Is there such thing as "too much data" into the USB ports? The state machine and rotary module are plugged into their own USB ports, no hubs (although a lot of other things are on USB hubs).

What do you reckon?
George

Josh

Hello George,

Thanks for constraining the issue! I'll try to replicate it on our end.
In the meanwhile, let's try this:

In /Bpod_Gen2/Functions/Internal Functions/ArCOM/ArComObject_Bpod.m
change line 155 from:

obj.Port = IOPort('OpenSerialPort', portString, ['ReceiveTimeout=3, BaudRate=' num2str(baudRate) ', OutputBufferSize=' num2str(obj.OutputBufferSize) ', InputBufferSize=' num2str(obj.InputBufferSize) ', DTR=1']);

to:

obj.Port = IOPort('OpenSerialPort', portString, ['ReceiveTimeout=3, BaudRate=' num2str(baudRate) ', OutputBufferSize=' num2str(obj.OutputBufferSize) ', InputBufferSize=' num2str(obj.InputBufferSize) ', DTR=1, PollLatency=0.0001, StartBackgroundRead=1']);

Please let me know if this helps - and I'll follow up if I can identify a different issue.

Thanks,
-Josh

George

Howdy,

Unfortunately that change didn't alter the behaviour. I fiddled with the PollLatency but that didn't change anything either.