Specifications

LBI-39000B COMPONENTS
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2.5. MD110 LIM
The MD110 is an Ericsson Private Branch Exchange (PBX). Its primary building block is the line interface module
(LIM). The LIM performs all call processing functions. One LIM interfaces to the PI and either the Public Switched
Telephone Network (PSTN) or another PBX. It contains two to four primary switching cards which connect to a common
backplane. The backplane includes a processor bus and a device bus. The processor bus carries control data between the
device processors on the individual boards. The device bus carries voice or data to and from device boards.
In addition to the LIM, the standard MD110 has an alarm unit, an Ericsson dial-back modem for remote configuration, a
two-hour battery back-up, and up to eight on-premises extensions that allow a telephone to be directly connected to the
MD110 for testing purposes. A 386 PC for configuring the MD110 is optional.
The MD110 also has one or more termination lines to the PSTN or another PBX. All types of digital and analog trunks
and tie lines are available based on customer needs. In addition, the MD110 always has one digital ISDN T1 or E1 trunk for
connecting to the PI.
The MD110 system requires specific environmental conditions to ensure proper operation. The MD110 should not be
installed in a location where water sprinklers are present. As an alternative, Halon is the recommended fire protection system.
If static electricity is generated by the floor covering, the floor should be covered with suitable antistatic material to reduce
the risk of disturbances to the MD110.
The following normal operating and storage limits must be maintained to ensure proper MD110 operation:
Temperature range: 41 to 104°F (5 to 40°C)
Recommended state: 72 ± 2°F (22.2 ± 1.1°C)
Relative humidity range: 20 to 80%
Recommended state: 50 ± 10%
Before power is applied to an MD110 system, the equipment and the ambient room temperature/humidity must be stable
within the operating ranges. Measurements should be taken at least 60 inches above the floor and at least 20 inches from any
heat dissipating object. Typical heat dissipation for MD110 cabinets is 300W. This value recognizes that some of the power
supplied to the system rectifiers is actually dissipated over cabling and external station equipment.
The type of air filtration required for proper operation depends upon the dust and other particulate matter concentrated in
the equipment room. In a high particle-count atmosphere, use of a prefilter and a main filter in the room ventilation intake is
required. If salt air, corrosive gases, or other degrading pollutants are present, special filtering is required. Air in the
equipment room should circulate to prevent hot spots and to exhaust heated air. To be safe, circulation equipment should
change the equipment room air every 5 minutes. The circulating air should contain from 5 to 25% filtered fresh air.
Dimensions of MD110 equipment cabinets are as follows:
Height: 62.1"
Width: 27.1"
Depth: 13.4"
Floor loading is based on a 36-inch deep aisle working space in front of each cabinet and is derived from total cabinet
weight. The maximum weight of a fully loaded LIM cabinet is 440 lb. The cabinet floor loading for MD110/50 cabinets is
approximately 47.3 lb/sq ft.