Troubleshooting10-410.2 What to DO If an Error Occurs(For Each Communication Mode)10.2.1 When Using PLC Link Function What to do If an error occursSituation Contents to check Confirmation methodIs a communication cassette attached? Check if the communication cassetteis attached firmly.Are wirings correct? Check the wirings again.Isn't there any problem in environments such asnoise? Check the shielding.Is the unit number of each unit set correctly?- Are the unit numbers set sequentially andconsecutively from 1?- Isn't there any overlapping unit number?- Isn't any number over 17 used for unit numberwith PMSET instruction?Isn't there any overlapping transmission area foreach unit.Is the transmission/reception area of PLC linkcorrect?Is the maximum unit number used for the PLClink correct?Communication is notpossible.(For the serialcommunication unit, theERROR LED turns on.)Is the communication mode set correctly?- Check the configuration (COM.1settings) of the CPU with built-in SCUunit or the serial communication unit.- Check the communicationparameters with PMGET instruction.(Note)(Note) For checking communication parameters with PMGET instruction, the CPU should be set in the RUN mode.Set "Mode selection when self-diagnostic error occurs - A unit error occurred." to "Continue operation" in theCPU configuration.10.2.2 When Using MEWTOCOL/ MEWTOCOL7/ MODBUS-RTU Function What to do if an error occursSituation Contents to check Confirmation methodIs a communication cassette attached? Check if the communication cassetteis attached firmly.Are wirings correct? Check the wirings again.Isn't there any problem in environments such asnoise? Check the shielding.Communication is notpossible.(For the serialcommunication unit, theERROR LED turns on.)Is the communication mode set correctly?Are communication condition settings correct?Are unit numbers set correctly?Is the communication mode set correctly?Is the communication mode set to the samemode as that of a destination device?- Check the configuration (COM.1settings) of the CPU with built-in SCUor the serial communication unit.- Check the communicationparameters with PMGET instruction.(Note)Communication is notpossible when SD/RDLEDof communication cassetteis flashing.Is the command length for MEWTOCOL orMEWTOCOL-7 within the prescribed length?Check the programs of destinationdevices.(Note) For checking communication parameters with PMGET instruction, the CPU should be set in the RUN mode.Set "Mode selection when self-diagnostic error occurs - A unit error occurred." to "Continue operation" in theCPU configuration.Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.clrwtr.com - Email: info@clrwtr.com
