How to clear the memory/perform factory reset of a M580 standalone (not Hot Standby) CPU for which the password was forgotten.
Issue :
The standalone M580 CPU is password protected and the password has been lost. We just want to recover the CPU and do not care about retrieving the project running in the PLC.
Product Line :
Control Expert
M580 standalone (not Hot Standby)
Cause :
Somebody password protected the application running in the M580 and nobody remembers that password.
Resolution :
Here are the steps to follow to completely wipe the memory of the M580 so that you can connect again to load a new application in it:
1- Remove power from the CPU rack
2- Physically move the CPU from being in slot 0 and 1 of the backplane to position 1 and 2
3- Apply power to the CPU rack
4- Connect the USB cable
5- Connect to the PLC using the USB method
6- Once connected, go to PLC -> Project Backup and use Backup Clear
7- Press "OK" on this menu
8- If done correctly, you should now see this icon in the status bar
9- Disconnect from PLC, but DO NOT backup the PLC project
10- Remove power from the CPU rack
11- Physically move the CPU back to slot 0 and 1
12- Apply power to the CPU rack
13- You should now be able to connect to the PLC without being asked for a password. The PLC should also now be in a "NO CONF" state
NOTE : If on step 5 you see this message pop up
then this procedure will not work as the CPU connection was also encrypted using the Engineering Link feature available in Control Expert 16.0 and latter.
In this situation, please refer to this FAQ:
https://www.se.com/ca/en/faqs/FAQ000272937/