Why I do not succeed to operate a memory (%M and %MW) transfer from SD card to the M221 controller ?

A script command file named script.cmd, present into the SD card and having the line Download “/usr/mem" make possible a transfer into the M221 PLC of %MW and %M values (see Modicon M221 Logic Controller - Programming Guide, section Memory Management: Backing Up and Restoring Controller Memory).



Nevertheless, there are some conditions to make this process being successfully achieved :

1) The script.cmd file should not include any other transfer command like application transfer command (Download “/usr/app") or firmware download (‘Download "/sys/os") which can be present into a script file automatically generated when doing:

• a clone operation (using an empty SD card)
• a ‘Backup from Controller’ operation command (commissioning Tab in SoMachine/Machine Expert - Basic)

2) The SD card has to be inserted into the M221 controller while it is already powered as the script  "Download “/usr/mem”  is not executed during the boot up, but read and executed by the firmware only when detecting the event of inserting the SD card.

Note: Those two mandatory conditions have to be kept in mind also for a memory upload operation, managed by the command line Upload “/usr/mem”

Released for: Schneider Electric Belgium