LBI-39190
6
VME CHASSIS
The 4U VME Chassis consists of the following components:
•
VME bus backplane
•
MVME147 microprocessor board
•
One or two VCOM24 microprocessor board(s) depending on configuration.
•
3.5” hard disk drive
•
3.5” floppy disk drive
The MVME147 board and VCOM24 board(s) are connected to IO modules at the back of chassis which have
connection points for console terminal, a printer, the Ethernet LAN and RF control stations. The microprocessor
boards and IO modules are mounted horizontally in the chassis. Each VCOM24 board has four DB25 type
female connectors providing four RS-232 serial communication channels. Each channel is connected to a single
RF control station in a radio shelf.
The VME chassis has an internal power supply system. The AC input circuitry of the power supply is auto
ranging, capable of using 90 - 132 VAC at 47 - 65 Hz or 180 - 264 VAC at 47 - 65 Hz. The power supply has
remote sense lines for all three DC outputs (+5V, +12V, -12V), and includes an AC “POWER ON” solid state
LED indicator.
RF CONTROL STATIONS
An RF control station is an EDACS mobile radio with a built-in Radio Data Interface (RDI). Data Advantage
uses RF control stations to transmit and receive data calls on an EDACS RF channel. Each RF control station is
housed in a shelf, and each shelf contains two RF control stations.
There are two or four RF control station shelves which are rack mountable shelf assemblies. The control heads of
radios are visible from the front of the shelf when the cabinet door is open. Also, the front of the shelf has a DB9
connector and a two position switch for programming purposes. The rear of the shelf has a power connector, an
8-pin modular connector and an antenna connector for each radio in that shelf.
RF CONTROL STATION POWER SUPPLY
One or two external power supplies power the RF control stations in Data Advantage. The power system
performs AC/DC conversion. The output of each power supply is connected to a power distribution panel which
provides up to seven 13.6 VDC outputs to RF control stations (only four are used).