PMP Synchronization Solutions User Guide CMM PlanningPMP-0297 007v001 (January, 2017) 3-18With PMP 54400 APs, the radio uses up to 12 W at 30 VDC and the input voltage as measured atthe "29 VDC" terminals on the CMM4 must be between 28 and 32 VDC to support 8 APs at themaximum 100 m (328 ft) Ethernet cable length.When supporting 56 VDC systems, the input voltage as measured at the “56 VDC” terminals onthe CMM4 must be between 44 and 59 VDC.The CMM4 controller board provides two 20 VDC outputs – one for the EtherWAN switch, and oneoptionally available for powering another low power device mounted in the enclosure by theoperator, such as a fiber-to-copper media converter. Total 20 VDC accessory power should notexceed 20 W.In cases where -48 VDC power is available and powering from the -48 VDC is desired (for example,in some telecommunications huts), procure a -48 VDC to +56 VDC converter such as a Mean WellModel SD-350C-48 and install between the -48 VDC source and the +56 VDC power supply.EU Countries OnlyTo enable regulatory compliance with the European Union (EU) directives, apower line filter module must be installed on the DC side of the power supply.This module may be ordered from Cambium Networks (part numberN000000L056A). Please reference section EU countries only – power line filtermodule installation on page 3-55.Syncing Two Co-located CMMs TogetherTwo CMMs can be synced together to meet either of the following goals:• Case 1 – One GPS antenna for two CMMs: Use a single GPS antenna to support two CMMs.This can be advantageous for a site with 2 CMMs where the site owner is charging perantenna and the operator wishes to minimize site costs by only installing one GPS antenna.• Case 2 - Redundant Sync: Take advantage of co-located CMMs, each with its own antenna, toprovide “warm spare” redundant sync. If one GPS antenna, coax cable, or GPS module hasproblems, remote re-configuration can re-establish sync to that CMM.The CMMs can be any combination of CMMs - either two CMM4s, two CMMmicros, or a CMM4and a CMMmicro.Syncing two CMMs together requires connecting their RJ-11 auxiliary ports together with a 6-wirecable and configuring each CMM appropriately. The location of the RJ-11 auxiliary port is shownin Figure 3.The connection cable is a special cable, not a straight-through cable. See page 3-23 forinformation on the cable and Figure 11 for cable pinouts.
