cqm1h proplem

hiii
my plc is omron cpu cqm1h, when make change in my program on line ,program work ok and after plc power turn off and retain to turn on my changes are cancelled and program retain to its original program ,
i want whate is the reason

I don't use the CQM1H, so I don't have any Manuals here for them.
However, it sounds like it is reloading the program from an EPROM, or a Flash Card mounted in the PLC.
Have a look at the manual, see if you have an on of those in the PLC, and the procedure for writing your changes to it if you want to make the changes permanent.

Hope that helps.

Stu.....

Dip Switch Setting

Check your dip switch setting for number 5. I had the same problem some time back. I think if it is in the ON postiion the program reloads from its MMC card at power up. When it is in the OFF position it will be held with the battery back up. If this is not it check your battery.

Good luck and let me kow how it turns out.

thanks for your reply
i tried to change dip 5 but not work ,so i change all dips off except dips on ,and it work ok

ahmed yousri said:

thanks for your reply
i tried to change dip 5 but not work ,so i change all dips off except dips on ,and it work ok

Click to expand...

You are very luck!

ahmed yousri said:

thanks for your reply
i tried to change dip 5 but not work ,so i change all dips off except dips on ,and it work ok

Click to expand...

hanqin said:

You are very luck!

Click to expand...

oh sorry i mean ,
i tried to change dip 5 but not work ,so i change all dips off except dip 3 on , according to manual

Did you try powering the PLC down and then back on?

On the CQM1H, you have to save the any changes to the program, to the EEPROM by forcing bit A14.00 ON while in the PROGRAM mode.

Turning DIP switch #2 to the ON or left position forces the CPU to load the program from the EEPROM into RAM upon powering up the PLC.

If you have not saved the program, then you will get the original program and lose your changes.

Turning DIP #2 to the right or OFF position does not reload the program from the EEPROM and therefore will operate with the most recent changes in RAM but that is not a good long term solution since if you were to lose power and the battery is dead, you will not have a program to run.