Omron PLC CPU Not Writing Configuration to ETN21

Hi all,

We've encountered a bit of a puzzling issue with an Omron CJ1M-CPU12 PLC on a site. Basically, it's not letting us write configuration changes to the ETN21 card on the rack.

All we want to do is change in the ETN21 is the IP address/subnet mask and add an IP address conversion entry. However, when we download the entire modified PLC program, the ladder code changes are updated but when we read the ETN21 configuration, it is unchanged.

When we try to transfer the ETN21 parameters separately with the 'Transfer[PC to Unit]' option, we get an error message that reads "Mode 11 - cannot download". I haven't been able to find any information on what this message means.

We have tried several spares of ETN21 cards, with different firmware versions (1.4 and 1.5) and we still encounter the same issue. This leads us to believe it is something to do with the Omron CPU. For whatever reason, it is not letting us modify the configuration of the Bus units.

Another thing is there is an identical Omron PLC on another site that has practically the same program and same rack and unit configuration. We were able to download those same program changes to that PLC last week with no issue at all. This makes me suspect some sort of hardware fault as the root of our woes.

Do any Omron experts hear have any idea what could be the possible causes of our issue?

http://www.fa.omron.com.cn/data_pdf/mnu/w420-e1-06_cs1w_cj1w-etn21.pdf?id=1992

I would start by getting the version number of the ETN21 card. Each card has slightly different specifications. See manual above.

Then I would go to '2-1 Overview of Startup Procedure' in the above manual to double check the settings.

Hope this helps,
Garry
http://www.accautomation.ca

Thanks for the info.

The customer had a spare CJ1M CPU unit, so we managed to resolve the issue by replacing the running CPU with the spare. Our guess is that the old CPU had some sort of flash memory issue where it wasn't able to write Unit configuration changes.

Just came across this post while trying to resolve the same issue.
The simple solution is to flip the ETN21 to ETN11 mode;
PLCIO Table, Highlight the ETN module and select Options, Change ETN mode.
This will flip the ETN mode from 21 to 11 (or 11 to 21 depending on your initial setting).
Then repeat the above to flip the ETN back to the desired mode and you should be able to download the settings.

Don't know why this works - I suspect its resetting something in the memory (?)