Motorola GM950E, Service Manual

Page: 221 / 228

Accessory Connector Details
External Device Connectors B-1
1.0 Accessory Connector Details
The 16-pin accessory connector pin functions are as follows:
* Factory default SWB+.
Pin 1.
- Speaker - audio
Speaker - and S (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.
Pin Name Type
A2
4-Channel
A3
128-Channel
1 SPKR- Analogue output
✓ ✓
2 Ext. Mic Audio Analogue input
✓ ✓
3 GP1 Digital input
✓ ✓
4 GP2 Digital output
✕ ✓
5 Flat TX Audio Analogue input
✕ ✓
6 BUS+ Digital i/o
✓ ✓
7 GND Ground
✓ ✓
8 GP3 Digital i/o
✕ ✓
9 GP4 Digital ip. capture
✕ ✓
10 Ignition sense Digital input
✓ ✓
11 RX Audio Analogue output
✕ ✓
12 GP5 Digital i/o
✕ ✓
13 * SW B+ / GND Analogue output
✕ ✓
14 GP6 Digital i/o
✕ ✓
15 RSSI Analogue output
✓
(Unbuffered)
✓
16 SPKR+ Analogue output
✓ ✓
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