Motorola GM950E Service Manual page 221

1.0 Accessory Connector Details
The 16-pin accessory connector pin functions are as follows:
* Factory default SWB+.
Pin 1.
- Speaker - audio
Speaker - and Speaker + (Pin 16) are used to connect an external speaker. The audio PA is a bridge
ampliÞer with a minimum load resistance of 3.2 ohms. The internal speaker can be disabled by
removing the control head. Disconnect the internal speaker and assemble the control head back to
the radio.
Pin 2.
- Microphone audio
This microphone signal input is common with the microphone signal input on the microphone con-
nector and is connected to the microphone path input of the AFIC. The nominal input level is 80mV
for 60% deviation. The DC impedance is 1100 ohms and the AC impedance is 1000 ohms
Note: Only one microphone should be connected at any one time.
Pin 3.
- General Purpose 1 (GP 1)
This is a digital input only. The RSS details which functions may be assigned to this pin by the code-
plug. The primary use for this pin will be external PTT. (See Note 1).
Pin 4.
- General purpose 2 (GP2)
This is a digital output only. The RSS details which functions may be assigned to this pin by the
codeplug. The primary use for this pin is as external alarm output (See Note 3).
Pin 5.
- Flat TX audio
This input is for injecting signals into the transmit path that should not be Þltered, e.g. the output of a
modem. The nominal input level is 150mVRMS for 60% deviation. The impedance is greater than
25kohms.
External Device Connectors
Pin Name
1 SPKR-
2 Ext. Mic Audio
3 GP1
4 GP2
5 Flat TX Audio
6 BUS+
7 GND
8 GP3
9 GP4
10 Ignition sense
11 RX Audio
12 GP5
13 * SW B+ / GND
14 GP6
15 RSSI
16 SPKR+
Type
4-Channel
Analogue output
Analogue input
Digital input
Digital output
Analogue input
Digital i/o
Ground
Digital i/o
Digital ip. capture
Digital input
Analogue output
Digital i/o
Analogue output
Digital i/o
Analogue output
(Unbuffered)
Analogue output
Accessory Connector Details
A2 A3
128-Channel
B-1