On, off, and auto in emergency transfer
This is introduced to set the state of emergency transfer, because a physical switch is not provided on the faceplate of the TN2312BP IPSI circuit pack to control the state of emergency transfer. The command for this is set emergency-xfr on | off | auto location
The TN2312BP IPSI supplies -48V DC voltage to an emergency transfer panel. This -48V supply keeps relays within the emergency transfer panel operating which, in turn, keep analog stations and CO trunks wired to ports (station and trunk respectively) on the system. When the TN2312BP IPSI is supplying -48V, the state of emergency transfer is off. When a problem is detected and the TN2312BP IPSI stops supplying -48V the state of emergency transfer is on. When the TN2312BP IPSI is in the auto state, it is usually supplying -48V to the emergency transfer panel, but automatically switches to the on state and stops supplying -48V if it detects a problem.