Specifications

Symptom:
RS-232 Module is not responding to commands
RS-485 Module is not responding to commands
Events counter not counting properly.
Error in displayed value.
Read Data (RD) values are factor of two times normal values.
Module responds with ?1 COMMAND ERROR to every command.
Characters in each response message appear as graphics characters
• RS-232 Module is not responding to commands
1. Using a voltmeter, measure the power supply voltage at the
+Vs and GND terminals to verify the power supply voltage is constantly
between +10 and +30Vdc.
2. Verify using an ohmmeter that there are no breaks in the
communications data lines.
3. Connect the module to the host computer and power-up each device
(module and computer) then using a voltmeter measure the voltage be-
tween RECEIVE and GND. This voltage should be approximately - 10Vdc.
Repeat the measurement between TRANSMIT and GND terminals and
confirm the voltage value to be approximately -10Vdc. If either of the two
readings is approximately 0.0Vdc then the communications data lines are
wired backwards. Proper communications levels on both TRANSMIT and
RECEIVE terminals should idle at -10Vdc.
4. If you are using a serial communications converter (A1000) ensure that
the communications Baud Rate switch is set to the proper Baud Rate value.
5. Confirm software communications settings in Host computer match
those values being used by the connected module(s).
6. If the Baud Rate value being used in the application is greater than 300
Baud and the module will only communicate 300 Baud then make sure that
the DEFAULT* terminal is not connected to Ground (GND).
7. If the module(s) are being used in a RS-232 daisy-chain communica-
tions configuration then ensure that the "Echo Bit" is enabled in the
setup(SU) message of each module.
8. If the problem is not corrected after completing the steps above then
connect the module by itself to a Host computer as outlined in Chapter 1.0
under "Quick Hook-up". Start the supplied Utility software and please call the
factory for further assistance.
Chapter 8
Troubleshooting