Keyence KV-40RW communication problem


Thread Starter

Luca Gallina

A customer has a machine controlled by a Keyence KV40-RW PLC.

The machine has been stored away for a while (perhaps more than one year) and then put to production again.

The PLC does not run, the POWER led is lit while the RUN led is off.

An HMI terminal connected to the PLC shows a "communication error" message.

I tried to connect to the PLC by using an RS232 link and the software available for free at Keyence web site, but I was unable to communicate with the CPU even using two different PCs.

I could replace the CPU with a new one, but I'd really like to be able to upload the program from the current PLC.

My question: is there anybody who can give me any clue? Is the CPU damaged or did I miss anything?

Thanks in advance,
Luca Gallina