Installation manual

60 MTM700/MTM800 Mobile Terminal / Installation Manual INSTALLATION

Connectors & Pin Assignment of the Radio

Transceiver Rear Side - Pin Function

Figure 25 Location of Accessory Connector and Expansion Connector - Rear Side

This section gives a description of the Accessory Connector and Expansion Connector pin func-

tions. The Expansion Connector provides a 4-wire RS232 interface for connecting Data Devices.

CAUTION: The accessory connections shown are not compatible to some other models of

Motorola radios. Check the appropriate accessory or technical manual for further

information.

Table 9 20-Pin Accessory Connector

Pin Function Description

1 EXTERNAL

SPEAKER -

Speaker - and Speaker + (Pin 16) are used to connect an external speaker. The audio

PA is a bridge amplifier with a minimum load resistance of 3.2 ohms.

2 EXTERNAL MIC

AUDIO

External-, Emergency-, or Hot-Microphone; depends on CPS programming. This microphone

signal is independent of the microphone signal on the microphone connector. The DC impedance

is 660 ohms and the AC impedance is 560 ohms.

3 EXTERNAL PTT This is a digital input to trigger external PTT; active low; non active high

4 EXTERNAL ALARM This is a digital output for External Alarm / Fault Indication; active low; open collector

with 4k7 Ohms pull up to B+

5 TX_AUDIO This input is intended for injecting signals into the transmit path. Input impedance > 10

k Ohms;

input level = 775mV

RMS

6 KEYFAIL / FLASH This line supports the encryption module and the flash mode.

Service Aids: 12 volts at this pin during power up/on brings the radio into the flash

mode.

7 ANALOG GROUND Analogue Ground

8 DIGITAL_GROUND Digital Ground

9 EMERGENCY To activate this functionality the pin has to be connected to ground. This will turn on the

radio.

1816141210

1715

13119753

864220

*Note the location of Pin 1

Accessory Connector

7 pin RS232 connector (MTM700 only)

C a u t i o n