LakeShore 335 problem

[Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Folks,

I am trying to get a LakeShore 335 temperature controller working with EPICS.  It has both GPIB and USB interfaces.  The USB operates as a serial port at 57600 baud, 7 data bits, odd parity.  Yesterday I connected it to the USB port on Linux, where it was seen as /dev/ttyUSB0.  I set up a udev rule to always connect that vendor, model, and serial number to /dev/lakeshore-335-1 with 666 permissions.  I loaded an IOC with both an asyn record for interactive testing, as well as the LakeShore335.db file which uses StreamDevice here: https://github.com/epics-modules/ip/blob/master/ipApp/Db/LakeShore335.db

Initially it worked fine, I could communicate both with the asynRecord and with the database.  However, after some time it stopped responding to any commands sent to it.  When I disconnect and reconnect the USB cable to the Linux machine it is immediately seen OK, it shows up in lsusb and the udev rule is being activated correctly, so I know the low-level USB interface on the device is working.  I have tried power-cycling several times.

Does anyone know why this might be happening?  There is a Remote/Local switch on the front panel, but it does not communicate in either mode.  Is there some setting that could have been flipped or something?

Thanks,

Mark