If you suspect that a PM600 module has a problem with the quartz sensor you can query the frequency counts with the below remote command.
This remote command does not work when the module is in the calibration sled. The modules must be installed in the pressure controller (normal operation method).
Send this command, where x is the slot number; slot 1=5, slot 2=15, slot3=25, slot4=35, slot 5=45
DIAG: VAL: PRESx?
Send the response(s) to technical support at Pressure Calibration Technical Support or submit a new ticket by the "Submit a request" link at the top of the page.
The command to read the pressure in the displayed pressure unit is, where x is the slot number (same as above),
See this article for remote commands to send to the auxiliary sensors in the 6270A chassis and PM modules,
6270A/8270A/8370A COMPASS database for troubleshooting sensors