cnPulse Introduction

cnPulse is a GPS sync generator used with a wide variety of Cambium radios to provide a precise 1PPS (Pulse Per Second) timing reference.  This timing reference is used by the radios to synchronize their transmit and receive cycles thereby reducing self-interference.

cnPulse replaces the uGPS in the portfolio and provides similar functionality with a few key differences. It is an all-outdoor IP67 rated module.  A detailed spec sheet is available here on the Cambium website:

cnPulse is typically deployed in one of three modes (refer to separate knowledge base articles for diagrams):

Mode 1: AUX Port:  In this case cnPulse is connected directly to the AUX port of a PMP 450/450i/450m access point.  Via this connection, the radio provides power to cnPulse and cnPulse sends the 1PPS sync signal along with statistics on the number of satellites currently visible.

Mode 2: CambiumSYNC: In this case cnPulse is connected 'in-line' with the CAT-5 drop cable between the radio's PoE input and the power injector.  cnPulse receives power and data input from the power injector and adds the sync signal to the physical layer connection.  The output of cnPulse in this case includes power, data and a CambiumSYNC signal that feeds directly into the power input of radios such as the ePMP 3000 and PTP 550.  This mode also works with the 450i/450m platforms but note that no GPS statistics are avaialble when using this interface.

Mode 3: CMM5.  When deploying a cluster of Access Points, the CMM5 can be used to distribute power and sync. This technique is very similar to the AUX mode above.  cnPulse is connected via a cable (N000000L125A) to the SYNC IN port on a CMM5 injector.  The 1PPS signal and GPS statistics are then available in the CMM5 controller GUI and SNMP interface.

Note that there is no software or configuration needed on cnPulse.  Simply connect the cables and the module seeks GPS signals and then starts generating the 1PPS signal.

5 Likes