SLC 5/03 DH485 and RS232 LEDs are off

[teal854t 0]

When i plug the power I only see RUN LED is on. Both DH485 and RS232 LEDs are off. I can not go online to PLC. It was working fine till someone did some changes in channel settings and downloaded it to PLC. After that no more communication. How can I get it back to online.

Thanks

[mikey431 3]

unless you know  what changed in the channel settings  ,it is not easy to get back in.If you are absolute sure you have the latest and correct PLC program ,you can reset the processor to factory default setting and re download the program.Check this forum thread for factory reset steps.Hope this helps!

http://forums.mrplc.com/index.php?/topic/13509-reset-503-to-factory-default-settings/#comment-66258

[teal854t 0]

Thank you. Got it.