1756-L71 loses program when powered down

[davidhinch]

I have a new L71 processor, 17 slot rack with 2 ENBT cards, Several I/O and M08SE card. Whenever the rack is powered down for more than an hour it loses the program. I get a Code 62 power up fault. Rockwell's typical answer "Update the firmware" I am running 20.018 already.

Any Ideas ?.... can I use the SD card for boot up ?

 

[jstolaruk]

Silly question but what is the state of the battery? SD card is fine but it won't restore lost data.

 

[jkerekes]

L71s don't have a battery to keep the program when powered off. When powering off it writes to non volatile memory.

 

[jstolaruk]

L71s don't have a battery to keep the program when powered off. When powering off it writes to non volatile memory.

Thanks. Seems strange that it takes at least an hour. Less than an hour and it retains it?
Then maybe try a firmware backdate and see if there is a change.

 

[nhatsen]

L7x controller use a Energy Storage Module (ESM), like a supercap. The main idea behind this is "eliminate the disposal hazards, maintenance and transportation issues associated with lithium batteries". With the ESM you have enough time to write important data to the SD Card.

Of course, you have to configure your controller for transferring the application from the SD card during startup.


TN 114726 Energy Storage Module (ESM) (Access Level: TechConnect)
https://rockwellautomation.custhelp.com/app/answers/detail/a_id/114726

 

[Contr_Conn]

Please refer to the TN 278692:
You need to contact Technical support again and provide the full image of the SD card.
It has debug details that should be investigated.
They may request an additional details including your ACD file.

Don't try to do this via chat or email - you will get the best results if you call.

 

[Operaghost]

It sounds like the ESM module is either not installed or it has failed. When you are online with the controller does the Online Toolbar show any messages regarding the Energy Storage Module?

There is also an SD card on these units. Is the SD card a Rockwell card, or has someone removed it or replaced it with a card from another manufacturer?


And to clarify......

When powering down, the ESM is supplying power to the RAM long enough to transfer the project from RAM to FLASH memory plus keep the clock up to date. Flash is NOT the SD card. The controller will work without the SD card.

The program can be transferred to the SD card, but it requires the user to manually do so and the controller must be in Program mode. It is not automatic as the project on the SD card is intended as your "safe" backup.

The SD card can be setup to automatically load from the SD to RAM on power up, but it must be configured to do so.

OG