Issue:
Unable to connect to M580 because the password was forgotten and the Engineering Link mode was set to "Enforced".
When Engineering Link is set to Enforced, you are forced to create an application password. Also the only protocols that can now be used to connect are:
HTTPS
HTTPS via USB
when using those protocols, you can no longer use the SHIFT + F2 method to obtain a code that will allow engineering to provide a recovery password if you forget the application password.
Also the method of moving the CPU one slot over to the right does not work in this mode.
We are left with no method of clearing the CPU back to NO CONF mode.
Products:
M580 CPU with firmware 4.20 and up
Control Expert 16.0 and up
Resolution:
There are 2 methods that can allow us to recover the CPU with an "Enforced" engineering link.
Method 1 : This method will require you to know the password for the firmware update.
Using EcoStruxure Automation Device Maintenance, you can downgrade the CPU back to firmware 4.10. Since this version did not support the Engineering link feature, the CPU will reject and erase the application when downgrading.
Method 2 : This will require an M580 SD card (BMXRMS004GPF) and a spare M580 CPU of the same model
In the spare CPU, create an application with no application password. The engineering link mode might have to be set to "Full Access". Make sure to insert the SD card in the CPU before transferring this application in the spare CPU.
Once this is done, power down the spare CPU and retrieve the SD card.
Power down the "locked" CPU and insert the SD card.
Power the CPU back up. The program in the SD card will overwrite the one in the CPU, effectively replacing the application with the "Enforced" option.
