Faulty SLC500 CPU?

[PreludeJai]

Hi all, i got a SLC500 CPU and somehow i cant communicate with it. Once i powered on, all LEDs are flashing. it was working fine before the power has been switch OFF and back ON quickly at the site. i wonder will that causing damage for the CPU?

thanks,

 

[dmroeder]

Which SLC is it? (5/01, 5/02, 5/03 ect...)

Could you better describe the LED's? What color are they?

 

[PreludeJai]

It is a SLC 5/04 CPU. I cant remember what colour are they. All i can remember is all the LEDs are flashing at the same time.

 

[dmroeder]

It is a SLC 5/04 CPU. I cant remember what colour are they. All i can remember is all the LEDs are flashing at the same time.

I've seen a lot of strange things with PLC's, but I've never seen all LED's flash in sync on a SLC. If you are lucky, maybe you could clear the memory. You should be able to do it by unplugging the battery and shorting the big capacitor next to the battery connection. You would probably have to remove the memory module if you have one.

The processor is not actually running anything is it? I can't imagine that it is by the sounds of it.

 

[geniusintraining]

See here... it may help http://www.plctalk.net/qanda/showthread.php?t=43795

Mine was a bad CPU, its now my test PLC, cycle power several time and it works.

 

[Mickey]

If all are flashing. That would point me to the power supply.

 

[PreludeJai]

THANKS geniusintraining. i will try your way and see.

 

[PreludeJai]

the power supply are working fine. coz we have a spare unit to replaced and nothing wrong with it.

so that would be CPU problem i guess.

anyway thanks for your advice