Help in overwriting protected Omron PLC CP1H

Hi,

I have very limited knowledge in PLC. I uploaded the updated version of the software from our supplier on Omron PLC CP1H.

It was also UM read protected and Task Read Protected and the password was known. Also the option of overwriting prohibited on read protected was check marked.

I did not think it would be a major issue since I know the password, and uploaded it.

However, now, when I try to access it, it says read protected and upon entering the read protection password, it accepts, but does not actually unlock.

Please help on the correct procedure.

VB

Welcome to the forum.

Check Dip Switch 1, it should be OFF.

Hope this will help.

Thanks for the prompt reply.

I checked, DIP switch 1 is at OFF position.

Can you please tell me if its possible to do a hard reset / force memory wipe and reprogram the PLC, since I already have the software?

Thanks

I do not think there is a way to do that with the software.

I would suggest you power down the plc, and remove the battery for at least 8 hours. This should allow the memory to reset.

Hope this will help.

Thanks a lot, I will try this and revert.

vb1095 said:

Hi,
... upon entering the read protection password, it accepts, but does not actually unlock.
VB

Click to expand...

What do you mean by this?
For me, does not unlock means does not accept.

Sergei Troizky said:

What do you mean by this?
For me, does not unlock means does not accept.

Click to expand...

Thanks for your reply.

I understand what you are trying to say. However, when I enter the UM read protection password, the dialogue box says UM read protection removed.

But when I try to read the PLC, it comes up with the same error, UM read protected. I am also unable to clear memory.

So, I am back to where I began. It does appear weird, and hence seeking your help, that maybe I am not doing something right.

There are 2 areas that can be password protected - maybe both need the password?

Solved

Hi everyone,

Thanks for your all your help. After some tinkering I found the solution.

Although it had only 1 UM read protection password, I found that one of the program modules had the task read protected option checked, which was responsible for this issue.

Once I unchecked it, all was well. I was able to clear the memory and load the new program.

Thanks again!

-VB