I/O bus error

[qayyumfaiz 0]

Dear all, i am using Omron PLC havin CPU CJ1M and three I/O modules i.e. first one is the digital input module ID211 the second one is relay output module OC201 the the last on is Analog output module MAD42. whenever the system is turned ON the error LED on the CPU unit lights up and stays ON indicating FATAL error i have checked in the manual the remedy of this error message and tried it as well but still the system sustain the fault status and doesn't moves to the next state i have tried the remedies illustrated in the user manual of this CPU but it didn't turned out to be successful. moreover it was stated in the manual that the error Flag having the following address 80CF is turned ON due to this Flag the error LOG keeps on showing the error message of "I/O bus error"............. what else i can do to over come this error.. please help me out.... waiting for your generous replies.........

[PdL 71]

Do you have an end cap attached and are all orange slides in lock position and cards are properly joined?

[Geir 4]

and have you successfully created a new IO-table?

[qayyumfaiz 0]

yes end cap is attached and all the locks are in their position and also I/o table is created as well but still the error sustains........... is there any possibility that one of the modules may have been out of order due to which i am having this problem because i have tried it by removing the modules the error is then removed but whenever i booty the input and the output module wither one of them the error again lights up....

[Geir 4]

You could try various combinations and positions of the IO modules to find the dodgy one. Remember to build IO-table between each try... At our school we have approx 15 CJ1/2 PLCs with various IO modules that we use for exercises, and over the years, we have had surprisingly few failures, considering the abuse by our students :)