Step 3. Diagnose Communication Problems

If the read or write request fails, a message is displayed in the status message field giving an indication of the failure. Use this information to help diagnose communication problems. Error messages will include the Error Code returned from the target programmable controller where appropriate. Refer to the Mitsubishi A-Series programmable controller's or Computer Link Module's User Manuals for complete error descriptions. Errors will indicate possible problems with data addresses, data ranges, etc.

Time-out errors

Time-out errors may indicate an invalid programmable controller address, incorrect communication parameters settings, or communication port problems. The most common cause of time-out errors is an improperly constructed communication cable.