SETSYSTEM 252

[MikeKitch68]

I am not able to get the SETSYSTEM 252, 0 working properly.  It does not back up the data variables.  In the documentation, it states the following:

Nano-10 allows you to do so easily using a single SETSYSTEM command, as follow:
SETSYSTEM 252, 0
Upon execution of the above command, the Nano-10 CPU will erase a special flash memory area used to
backup the pseudo EEPROM and it will then copy the entire pseudo EEPROM memory data to the flash
memory

[support]

What data variable are you trying to backup? Did you run the SAVE_EEP command to save the variable?

SETSYSTEM 252,0 is to backup the data that have been saved using the SAVE_EEP command to flash memory. These are pseudo EEPROM for PLC that are not equipped with the FRAM-RTC-xxx.

The saved data must be read back into the variable using the LOAD_EEP that you can run using a C.F triggered by the 1st.Scan pulse.

Please ensure that the same address is used for SAVE_EEP and LOAD_EEP.

[MikeKitch68]

I am doing the Save_EEP and Load_EEP functions but thought with the way it was stated, I could use the single step by itself.

We are trying to save the DM registers on Power Failure, we are doing a ForNext to save all DM (SAVE_EEP) when a power failure is detected.

Would that be the best way?

Thanks

[support]

How many DMs are you trying to save? If you have a lot of DM then it is best to use the FRAM-RTC-0 which can be made non-volatile by turning on jumper 1. That means basically all the DM will retain their data after a power failure.

As explained in the manual one should avoid using power failure interrupt to save pseudo EEPROM data into the flash memory. This is because it takes time to erase the flash and to save the data. If the PLC loses operating power before it could complete the save to the flash then you are likely to lose data.

FRAM-RTC-xxx on the other hand are non volatile Ferromagnetic RAM so data stored there are automatically non volatile.

[MikeKitch68]

We need to back up almost all of the DM registers.  We are doing some data collection with the unit.  We will look at getting the RTC unit.  Thanks for all your help on this.

[support]

You are most Welcome!

If you are doing data collection you may also want to consider if the FRAM-RTC-256 will work well for you.

FRAM-RTC-256  comes with 256K bytes of file space where you can save your data to files in text or CSV format. The file can then be uploaded to a FTP server (on a LAN or in the cloud) periodically and the stored file can be imported directly into Excel spreadsheet.  The uploaded data file could be given a date-stamped or  time-stamped file name so that it create a trail of historic data files for safe keeping on remote server.

Please refer to Chapter 18 of Nano-10 User's Manual for more details and sample programs if you wish to explore this idea.