PLC 5/20E Program Download


Thread Starter

Jason Chen

We use 9 sets of AB PLC 5 under Ethernet in my factory. One 20/E lost program now, I want to download it from DH+, but the error message is:
"Cannot get Connected to Online Processor!
DiagnosticStatus failed: Sts=0x02
Link Layer Timed Out(No Reply) or Recieved a NAK"

What's the root cause? Your reply is greatly appreciated!!
I had a 5-40e that would do the same thing the only way I could re-download the program is to do it from a direct connect at the processer. never did find out why it kept loosing the memory. when it lost the memory all the ip address was lost also.

Ian Campbell-Kelly

Some early series/firmware versions of PLC5 Ethernet processors have a fault that clears the memory when sudden very high Ethernet network loads occur. I would guess it doesn't reject corrupt or fragmented data packets properly. Get the PLC firmware updated - a return to A-B job, usually chargeable. Going to the latest version of firmware on the same series is fairly cheap, but upgrading the PLC to the latest series is very expensive. (If you're an A-B user you'll understand the difference!) The cheap one should fix the problem.