User's Manual

Hot Standby Operation
RFI-148 & RFI-900 High Output Power Paging Transmitters User Manual Page 50 of 134
7.5 Hardware Feedback
Three open-collector MOSFET outputs report a summary of the unit state:
• PHSB MISSING (LIU pin 4): Active when a Hot Standby mode is configured and the RFI-PHSB
cannot be detected
• IN STANDBY (LIU pin 23): Active when the unit is in Standby mode (ie, PTT disabled)
• IS PRIMARY (LIU pin 24): Active if the unit is the Primary unit
Encoder Interface -> External I/O