cnPulse - Synchronizing two 450 radios
Question:
Cambium's new cnPulse GPS module appears to have just one port with AUX output. Does this mean we only can use this for one PMP450 and not two as we are used to with the old uGPS module?
Description:
Cambium's new cnPulse synchronization module has two modes of operation:
Mode 1: AUX Serial mode (uses cnPulse port 1)
cnPulse derives power input from the radio or CMM port and returns the 1PPS signal and satellite statistics on port 1. Typically used on CMM5, cnReach and the AUX ports on PMP 450i, PMP450m or PTP 450i
Mode 2: CambiumSYNC In-line mode (uses cnPulse port 2 and port 3)
cnPulse is deployed in-line with the radio’s CAT-5 drop cable. cnPulse receives power (and data) from the ODU’s PoE power injector on port 3. cnPulse port 2 then outputs PoE+Data+CambiumSYNC to the main input on a radio. Typically used on PTP 550.
Solution:
When deploying multiple PMP 450i or PMP 450m AP's on a tower, it is possible to use one cnPulse module to synchronize both radios. This is done by connecting ODU 1 via the AUX port mode and ODU 2 via the in-line CambiumSYNC mode. In this configuration the power to cnPulse is redundant and resilient. If the ODU providing power from the AUX port fails, the cnPulse will continue to operate from the power provided via the in-line POE power. The resilience applies in the opposite direction as well, and switchover is immediate and non-disrupting. See the diagram below.
This is different from the way it was done previously with the uGPS module. The uGPS used both AUX ports but required a separate power supply to power the uGPS. With cnPulse, there is no need for a separate power supply.