Troubleshooting tips – Precision Digital PD865 User Manual
Page 68

PD865 Snooper Modbus
Serial Input Meter
Instruction Manual
68
Troubleshooting Tips
Symptom Check/Action
No display at all.
Check power at power connector. 
Check fuses (not supplied). 
Not able to change setup or 
programming, LoCd is displayed. 
Meter is locked, enter correct four-digit 
password to unlock. 
Meter displays error message 
during scaling (error). 
Check input points for similar values.
Master displays a different value 
than PD865 display. 
Check master data type setting. Make 
sure it matches the PD865 data type 
found in the Register Table. 
PD865 Master displays a different 
value than slave device. 
Check PD865 data type setting. Make 
sure it matches the slave data type. 
PD865 Snooper mode going into 
communication break 
Increase baud rate and/or poll time.
Display alternates between:
1.
Hi and a number
2.
Lo and a number
Press Menu to exit Max/Min display 
readings. 
Display flashes -199999.
The data is less than the Input 1 value. 
Use a lower value for Input 1. 
Display flashes 999999.
The data is greater than the last Input 
point value. Use a higher value for the 
last Input point. 
Display response is too slow.
Check filter and bypass values.
Relay operation is reversed.
Check: 
1. Fail-safe in Setup menu. 
2. Wiring of relay contacts. 
Relay and status LED do not 
respond to signal. 
Check: 
1. Relay action in Setup menu. 
2. Set and reset points. 
Meter is not communicating.
Check: 
1. Serial cabling (swapped lines). 
2. Slave ID, parity, and baud rate. 
Meter display occasionally jumps 
to another value. 
Check that the polling time is not too 
fast for the chosen baud rate. For 
example, a polling time of 0.1 seconds 
is too fast for 2400 baud. 
The display locks up or the meter 
does not respond at all. 
Cycle the power to reboot the 
microprocessor. 
Other symptoms not described 
above 
Call Technical Support for assistance.
