User's Manual

80 MDS Master Station MDS 05-6399A01, Rev. D
7.2 Redundant Units
The active radio can be identified by the corresponding LED on the alarm/relay module as well as the
active LED on the radio module. The active unit is normally selected automatically. For troubleshooting,
the toggle switch can be used to manually set the active radio. Alternatively, the switch can remain in the
automatic position, and the active radio can be selected via the SD Manager UI.
7.3 Technical Assistance
Factory technical assistance is available by contacting GE MDS during business hours (8:30 AM to 6:00
PM Eastern Time). For telephone assistance, call [phone], or visit our website at www.gemds.com
for additional contact options.
7.4 Replacing Modules
Component-level repair of a transceiver board in the field is not recommended due to the complex nature
of the circuitry and the use of surface-mount technology throughout the radio. You should return mal-
functioning assemblies to the factory (or authorized service center) for repair or replacement.
One approach to field-level servicing is to have spare modules available. Slide in modules are easily field
replaceable, including Power Supply, Radio, Platform Manger, and Alarm/Relay Modules. Internal Du-
plexers can also be replaced in the field. In this way, you can quickly remove and replace a defective as-
sembly with a working assembly. The following instructions describe the removal and installation of
these assemblies.
NOTE: When installing Power Supply or Radio Modules, torque thumbscrews to 10 in-lbs to insure op-
timum heat transfer through thermal contact connector on the rear of the unit.
7.4.1 Power Supply Modules
The two left-most card-slots on the MDS Master Station are dedicated to Power Supply Modules. To re-
move either of these assemblies, first disconnect the power supply cable. Loosen the two thumbscrews on
the front of the module, then slide the module straight out.
A Power Supply Module can be installed in either of the left-most slots on the Master Station. It will not
engage if an attempt is made to install into any other slot in the chassis. To install, align the Module with
the card guides and slide into the chassis until it engages with the backplane connectors. Push firmly on
the faceplate of the module to ensure a good connection and hand-tighten the thumb screws. The thumb
screws should be further tightened to 10 in-lbs to ensure optimum heat transfer through thermal contact
connector on the rear of the unit.
Connect the power cable first making certain that the supply is within the rating for the power supply
module you have installed.
6755
100-220 AC Power Supply Module
100-220 Vac, 50/60 Hz. 120W Max AC Power Supply Module.
6843
+/- 12-36 VDC Power Supply Module
+/- 12-36 Vdc. 10 A Max. DC Power Supply Module.
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.