S7-400H Program is deleted

jwborjas

Hello colleagues, we have encountered a rather strange and disturbing problem. In our system, each S7-400H PLC is made up of the following modules: 2PS 407 10A, 2 CPU 417-4H and 2 CP 443-1, all connected to redundant ET200 remotes, with new backup batteries, we make sure they were in good shape. The S7-400H was in normal operation, but at a factory stop we had to disconnect it from the power supply and when we reconnected it, surprise, the program was erased !!! . We have no idea what might be going on here, has something similar happened to someone? Thanks in advance. This case was reported by jm1983 in 2013. Whoever needs more details can read it in the forum looking for “S7-400H very strange problem” by jm1983. I have carried out the same tests mentioned there and I have not been able to solve the problem.

I appreciate your collaboration.

 Hello

Following questions

1.) what firmware version do you have on your PLC

2.) do you have a shutdown / startup procedure that you follow ?

I have several H Systems, but I have not seen this behavior.

Did you go online after startup to verify that the Program was "erased" and do you have any

diagnostic from the PLC you could share.

I have seen problems after power-down and then power-up if the Y-Link did not get established.

Also I am assuming you have a RAM Card in each PLC.

Regards / m.f.g

jwborjas

..............................

but at a factory stop we had to disconnect it from the power supply and when we reconnected it, surprise, the program was erased !!! .

........................

 Hello,

• Please tell us what type of your memory card. I guess it is a RAM and not EPROM.
• Please descripe in details how did you "disconnected if from the power supply"?v
  Did you removed CPU from the rack?
  Did you removed the Power supply from the rack?
  Did you removed battaries from the power supply while the power was off? If yes, how long the power supply was switched off without battaries?
• How did you know that your batteries is healthy? 
• Please check and ffedback us the setting of selector switch battery off on the Power Supply.
• Finally, please upload the diagnostic buffer of the CPU.

1. Cpu 417-4H (6ES7 417-4HL04-0AB0) Fimware: V4.0
2. Yes, under normal conditions.

But the problem arises when there is a complete power outage for major maintenance reasons.

The system enters its diagnostic routine (10 min) and performs a complete erase, yellow stop LED flashes at 2 Hz. When placed ON line there is no program block, except for the system blocks. I have to reload the user program again.

The system performs its startup and synchronization routines, goes into redundancy and everything operates normally.

Of course, I have a RAM Card in each PLC.

If you know of any way to upload this issue to Siemens engineers please let me know.

Thanks for your help

• Please tell us what type of your memory card. I guess it is a RAM and not EPROM.

Ans. This is RAM

• Please descripe in details how did you "disconnected if from the power supply"?

Ans. The problem has occurred when there is complete loss of energy

Did you removed CPU from the rack? No

Did you removed the Power supply from the rack? No

Did you removed battaries from the power supply while the power was off? No

If yes, how long the power supply was switched off without battaries?

• How did you know that your batteries is healthy?

Ans. I bought new batteries to discard discharged batteries, I performed the de-energizing procedure (short circuit for 2 sec), measurement of voltage at 3.6 volts. With the BATT.INDIC switch in position 2BATT and the batteries installed, the LEDs: BAF, BATT1F and BATT2F off. When uninstalling the BATT1, the BATT1F led turns on, when uninstalling the BATT2, the BATT2F led turns on, after a few seconds the BAF (red) LED turns on. When installing the batteries and pressing the FMR selector, the LEDs go out.

• Please check and ffedback us the setting of selector switch battery off on the Power Supply.

2BATT

• Finally, please upload the diagnostic buffer of the CPU

When I'm in the plant I take that information and send it to you

I suggest you check jm1983's post titled "S7-400H very strange problem" in this forum. This describes the behavior I have in my system.

Thanks for your attention.

jwborjas

1. Cpu 417-4H (6ES7 417-4HL04-0AB0) Fimware: V4.0
2. Yes, under normal conditions.

But the problem arises when there is a complete power outage for major maintenance reasons.

The system enters its diagnostic routine (10 min) and performs a complete erase, yellow stop LED flashes at 2 Hz. When placed ON line there is no program block, except for the system blocks. I have to reload the user program again.

The system performs its startup and synchronization routines, goes into redundancy and everything operates normally.

Of course, I have a RAM Card in each PLC.

If you know of any way to upload this issue to Siemens engineers please let me know.

Thanks for your help

 Hello.

What seems odd to me here is the following,

You have a H system with 2 independent Power supplies and 2 independent PLC,s and you are loosing the PLC program of both ??? PLC,s when you turn of the main supply and both PLC's are going through their startup / diagnostic routine.

If the backup battery's are ok on both PLC's, and you have not an issue with the back-plate connection, I don't see how his can happen.

Also your Firmware is 4.0, but what what revision. The current revision is 4.0.12. Please ensure you have the latest Firmware on both PLC's.

https://support.industry.siemens.com/cs/us/en/view/109474747 

You can also contact Siemens Support for some more help.

Regards / m.f.g

The Firmware is V4.0.9 

Very grateful for the help. 

jwborjas

The Firmware is V4.0.9 

Very grateful for the help. 

 Hello,

Please update the both CPUs to latest OS version.

Currently the latest is V4.0.12

You can download it from the link given above from (legacy support)

Hope this helps.

I have managed to maintain the program when there is loss of voltage, only when 1 or 2 batteries are installed in the source (PS) and the external power jack of the CPU is connected, adjusted to any voltage in the specified range, I set it to 12V. Only with batteries or only with external power the program is not supported. This is incredible . I did not want to perform the firmware update because I do not have the confidence that this cpu works properly. I would like this case to be reviewed by Siemens engineers and give an answer. Because the client I am serving cannot believe that the investment he made for his plant has this problem. 

Thanks for everything