Troubleshooting; Communication Troubleshooting; Generally; Specifically - Siemens SITRANS LR 300 Instruction Manual

Troubleshooting

Communication Troubleshooting

Generally:

1. Check the following:
• There is power at the unit
• The LCD shows the relevant data
• The device can be programmed using the hand programmer
2. Check the wiring pin-outs and verify that the connection is correct.
3. Verify that values in set-up parameters P770 to P773 match the settings in the
computer communicating with the unit.
4. Check that the port you are using on the computer is correct. Sometimes trying a
different Modbus driver will solve the problem. An easy stand-alone driver called
ModScan32 is available from Win-Tech at www.win-tech.com. We have found that
this driver is useful to test communications.

Specifically:

If you try to set an SITRANS LR 300 parameter via remote communications, but the
parameter remains unchanged:
• Some parameters can only be changed when the device is not scanning. Try putting
the device in program mode using the operating mode function.
• Try setting the parameter from the keypad. (First make sure that the lock parameter
[P000] is set to 1954.)
• The communications control parameter P799 must be set to 1 to be able to write
parameters to the SITRANS LR 300.
7ML19985CL02 SITRANS LR 300 – INSTRUCTION MANUAL Page 91