weewx-rtldavis rtldavis process stalled every 150 seconds

[arg...@xplornet.ca]

i installed weewx-davis on raspberry pi 3b via Vince Skahan's install script.   syslog shows packets being received every 3 seconds but every 150 seconds weewx stops the rtldavis driver with "Caught WeeWxIOError: rtldavis process stalled"  

Has anyone seen this before?  log file is attached.

Thanks John