Hello,

We   have one  PLC with CPU 414-2 and don't work the bakup sytem, Always switch off the main power all program  lost.

I tested  with a batteries connected directly in the front jack for the CPU, and have a same problem.

So I opened the CPU and I not know witch memories is for the program backup, Is the 7 memories in the botom for the board?  "K4M28163LH" .

Anyone know what tension they should have about these memories with normal power and after switch off?

Please anyone  know the component 454AB small CI with 6 pins.

does anyone know the component.

Thanks

Carlos S. Oechsler

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Split from S7-400 CPU Speed.

oechsler

Hello,

We   have one  PLC with CPU 414-2 and don't work the bakup sytem, Always switch off the main power all program  lost.

I tested  with a batteries connected directly in the front jack for the CPU, and have a same problem.

So I opened the CPU and I not know witch memories is for the program backup, Is the 7 memories in the botom for the board?  "K4M28163LH" .

Anyone know what tension they should have about these memories with normal power and after switch off?

Please anyone  know the component 454AB small CI with 6 pins.

does anyone know the component.

Thanks

Carlos S. Oechsler

------------------------------------------------------------------------------------------
Split from S7-400 CPU Speed.

 Hello,

perhaps you have a RAM installed on the bay of the CPU?

Which memory cards can you use with a S7-400 CPU? - ID: 73159687 ... 

 there is a rectangular blue

below is for S7 300 on the left you see the same in S7 400 (outside) it is longer (inside)

Which memory cards can you use with a S7-300 CPU?

Hello all,

we use a flash memory 6SE7 952 0KH00-0AA0.

The problem is Always when we switch de power supply off all parameters for the setup  and user program lost, 1 minute later the cpu startup because use parameter for the flash card, but the operator parameters going to the value save in the flash, than we need reinstall the actual parameters, ex: actual diameters for the rolls, turns etc.

This fact  occurs because the backup voltage is missing on the RAM Memories, "K4M28163LH"

The main board have one small IC with 6 pins "454AB" and the pin 3 must be have a batery tension  but do not have. I need a lay out for this connection for check.

See attach the cpu Picture

One question more?

Have in the cpu programm some parameters to refer a backup adjust?  yes or no

Carlos

Did You get any solution? Also mine cpu's losing the program after switch the power off. Batteries are ok. Firmware 4.0.09.

Regards

Bart

Marcjan

Hello,

Try to provide backup power by the jackplug at the front of your CPU first.

If that works, you have a faulty powersupply.

If it doesn't, replace cpu.

Regards,

Marcjan

I've made test on 3 different power supplies, 2 of them was new, one was dismantled from working device. Anyway, I think that is great idea to try that via jackplug, maybe there is possibility to damage the rack? First activities was done when I find out that cpu's are empty.

Regards

Bart

dchartier

Hello oeschler;

One question that comes to mind is: how dod you transfer the program to your flash card? A simple download only works with RAM memory. For a Flash memoru card, you must put the CPU in Stop mode. And use the Step 7 menu command "Load user program to memory card".

https://support.industry.siemens.com/cs/ww/en/view/23670531

If you choose to follow Marcjan's excellent suggestion to test your power supply module, you can provide external battery support to the PLC using a jack connector (we purchased a standard audio jack) on the bottom of the CPU, connected to a 9V battery. At least this is how we used this in the olden days... this allowed us to remove the CPU from the rack without loosing the RAM memory.

Recently, Siemens offers a dedicated jack for this purpose:

https://support.industry.siemens.com/cs/us/en/view/24525963

Hope this helps,

Daniel Chartier 

 Do You remember how long cpu's waking to be ready if program is onboard? Now it takes 10 min, and i thing the cpu uploading the program from other redudant. In case when everything is ok, its the same time or shorter?

Regards

Bart