Tyco Electronics MM102014V1 - Manual (Page 14)

MM102014V1, Rev. G
The radio uses a nominal amount of battery power when it is turned off. If the vehicle in
which the radio is installed is likely to be left unused for extended periods of time,
M/A-COM recommends installing Time-Delay Relay (p/n MAMROS0088) to prevent
excessive vehicle battery drain.
Finally, the TX/RX mini-UHF connector (half-duplex) provides connection for an RF antenna and the RX
port is capped with a nylon plug. For full-duplex radios, the RX port has a TNC connector output and
both RF ports and antenna are connected through an RF combiner.
Figure 3-3: M-803 Rear Panel (Half-Duplex Radio Shown)
3.10 CONTROL HEAD REAR PANEL
The rear panel of the CH-103 control head contains the interface connections necessary between the radio
and control unit. As shown in Figure 3-4, five connection points are:
• POWER - The DC power connector accepts vehicle battery power to power the unit and an
ignition/accessory control sense input for on/off control via the vehicles ignition switch/key.
• AUDIO – Provides connection to an external speaker.
• SERIAL – A serial port is provided to transfer data to and from a mobile data terminal or PC. It is
configured as a DTE device.
• CAN – The two 3-pin CAN connectors are used to connect the CH-103 (a CAN device) to the M-
803/V-TAC and to other control heads. These two connectors are connected in parallel to allow daisy
chaining of additional control heads. A terminator (supplied) must be connected to the unused CAN
port of the last control head.
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