Users Manual

MDS 05-6399A01, Rev. G MDS™ Master Station 125
6844 +/- 36-75 VDC Power Supply Module +/- 36-75 VDC. 3.5 A Max DC Power Supply Module.
6845 +/- 75-140 VDC Power Supply
Module
+/- 75-140 VDC. 2 A Max DC Power Supply Module.
DC power supply modules are available for several different input ranges.
These modules have interchangeable connectors. Make sure the supply is
within the rating for the module installed.
On a redundant unit equipped with two power supplies, a supply can be removed, and a new sup-
ply can be installed, while the unit is powered and operational. Do not remove power supplies
whose power source is still connected and active.
Peripheral Modules – including Platform Manager, Radio, Alarm, and Alarm Relay
Modules.
Peripheral slots on the Master Station include all slots between the power supply modules (on the
left) and the duplexer tray (on the right). On an MDS™ Master Station, the peripheral slots are
populated with the following modules, from left to right: Platform Manager, Radio Module, a
second Radio Module if redundant, and an Alarm Module or Alarm/Relay Module if redundant.
To remove peripheral modules, first disconnect cables attached to the faceplate of the module
you are removing. Label connections if necessary to remember how connections are made.
Loosen the two thumbscrews on the front of the module, then slide the module straight out, mov-
ing other cables out of the way as necessary.
The Radio Module heat spreader gets very hot under normal operating con-
ditions. Always use caution handling recently powered Radio Modules.
When removing a Radio Module, do not touch the heat spreader. It is recommended to pull the
Radio Module out only part way, disengaging the module from the backplane and rear heatsink,
and then allow the Radio Module to cool for several minutes before removing it fully from the
chassis.
To install a peripheral module, align the module with the card guides and slide into the chassis
until it engages with the backplane. Push firmly on the faceplate of the module to ensure a good
connection and hand-tighten the thumb screws. The thumb screws can be further tightened with a
screwdriver. Radio Modules should be tightened to 10 in-lbs, or approximately ¼ turn past hand
tight, to ensure optimum heat transfer through thermal contact connector on the rear of the unit.
Reconnect faceplate cabling connections to other modules as necessary.
Hot Swap Redundant Modules
On a redundant unit equipped with two Power Supplies and two Radio Modules, these modules
can be removed and/or installed while the unit is powered and operational. Replacing a Power
Supply does require first removing the supply input for the module, but the alternate Power Sup-
ply can remain powered. The unit will continue to operate using a single power supply.
When removing a Radio Module on a redundant unit, we recommend changing the selector
switch on the Alarm/Relay Module to lock the active radio to A or B as appropriate before re-
moving the other Radio Module. This should be done even if the desired radio is already active.