Message Exists But Visibility Value Does Not - Vaisala PWD22/52 User Manual

USER'S GUIDE____________________________________________________________________
94 __________________________________________________________________ M210543EN-E
- Take the maintenance PC (terminal), tools, and the calibrator set
with you.
4. Is PWD22/52 powered?
- Open the PWC22/52 electronics enclosure cover and see, if the
Run and Signal/Offset LEDs are blinking.
5. If no LED is on:
- Check the power supply voltage.
- Check that all the connectors are properly inserted.
- Check the power cable and connections.
6. If the Run LED is blinking (once per second for correct operation):
- Connect a maintenance terminal to the RS port.
- Check steps 1 and 2.
- Try resetting by turning the power off/on.
7. If the Run LED is lit:
- Try resetting as above.
- If the state is continues, it is probably caused by either the
program memory or CPU fault.
Message Exists but Visibility Value Does
Not
1. PWD22/52 control electronics is probably working.
- Check the status information with the STA command (see
section STA on page 73). If there are any active alarms, the
visibility value does not exist.
- Check especially P12, M12, BACKSCATTER and LEDI. See
Appendix A, Values for Internal Monitoring, on page 103 for
internal monitoring values of the limits.
2. Go to the PWD22/52 site.
- Check the cable connectors.
- Check the receiver and transmitter units. Follow the instructions
in section Removing and Replacing on page 86 when removing
the units.
- Visually inspect the condition of the electronics.