If a controller fails, you can remove its SD or microSD card and insert it into a replacement unit to keep your operations running. However, the removable card contains the system passphrase for the original unit, which will not match the passphrase for a replacement unit. This pass- phrase mismatch results in a boot sequence failing indicated by a Stat LED flashing with a 50% duty cycle and a 1 second period.
If you are monitoring the debug port, this notification banner opens in the serial shell.
To resolve this issue and successfully commission the replacement unit, you must use a serial connection to pre-configure the replacement controller with a system passphrase that matches the one stored on the removable memory card swapped out from the original unit.
Prerequisites:
- A controller has failed.
- You removed its memory card and inserted it into a replacement unit, but the replacement unit will not boot due to a passphrase mismatch.
- You are working in Workbench running on a PC that is on the same network as the controller. You know the passphrase for the original controller.
- Make a serial connection to the unit’s DEBUG port.
- Log in to the controller via the serial connection.
- The System Decrypt Failure Menu opens with the following options:
Update system passphrase
Remove all encrypted data
Reboot
Logout
- Choose
Update system passphrase.
- Enter the system passphrase for the original controller.
- Pre-configuring (via a serial connection) the replacement controller with a system passphrase that matches the one stored on the removable memory card (which you swapped out from the original unit) facilitates commissioning the replacement unit. In this situation, the commissioning process does not prompt for a passphrase since it detects a passphrase match.