Motorola MTM800 User Manual page 225

CONNECTOR PIN FUNCTIONS
Pin Function
17 HANDSET
18 GND
19 MIC_REAR_1
20 GPIO_4
21 USB_D+
22 USB_D-
23 RTS
24 CTS
25 PWR_ON
Table A-9 Pin assignment of the 25pin back connector – for RMC and MCC
Function
1
2
3
4
Idle
Description
GCAI PIN 3, Handset audio output, VOL ontrolled, AC coupled, min.
RL 150Ohm
GCAI PIN 5 GND
GCAI PIN 7 MIC Input 80mVrms Bias 9V= / 600Ohm
GCAI PIN 9 GPIO open collector, 15k to 3V3 PU, 5V tol. Output: see
GCAI spec. 1.20 Input: high > 2V, low < 0.5V
Second USB, D+
Second USB, D-
4 wire RS232 RTS, EIA/TIA-232 level
4 wire RS232 CTS, EIA/TIA-232 level
NGCH Power On input, high active, > 2V
Figure A-9 4 Level Analogue Input provided by GPI_7
Voltage Level (V)
0,00
1,25
2,50
3,75
5,00
Table A-10 Function of the voltage level at GPI_/
Tolerance (V) Default Function
0.000 - 0,625 Volume Up
0,625 - 1,875 Volume Down
1,875 - 3,125 Talk group Up
3,125 - 4,375 Talk group Down
4,375 - 5,000
Default
Parallel to front GCAI
Disabled
Hook Input
A - 11