Posted 20 Jun 2015 Dear All I have a PLC and a 1769-SM2 so the red led is Steady Red. in manual wroted about this error : Cause:The module is unable to establish communication with the controller. Corrective Action: Cycle power to the controller. now I want know what it means to Cycle power to the controller? means is I power off the controller and then power on it? if it is I do it and the problem exist. could you help me on this issue? Best Regards 1769-SM2.pdf Share this post Link to post Share on other sites
Posted 20 Jun 2015 yes, to cycle power means to turn off power, wait few seconds then turn the power on... since the connection to controller is through 'backplane', are you sure your CPU configuration is correct and all modules are correctly connected (and latched)? Share this post Link to post Share on other sites
Posted 20 Jun 2015 Dear Sir Thanks for your answer. Yea I ma sure. I has some test. for example I put this modules near to cpu and after it I put other I/Os. so in this configuration all I/O get error. so I put this modules in last of rack after other I/o. so in this configuration all I/O worked except This modules. I think the connection of this modules has problem. do you think same as me? Best Regards Share this post Link to post Share on other sites
Posted 21 Jun 2015 it is possible that module is faulty, check connections or replace it Share this post Link to post Share on other sites