March 23, 2006 6816812H01
3-4 Options and Accessories Installation: Dash-Mount Accessory Installation
1
This pin must be connected to ground by jumper on accessory cable if emergency is disabled, even if disabled by 
CPS. If enabled, this line must be grounded via a switch, which is normally closed. The emergency debounce time 
is programmable via CPS.
2
Pulling this line to ground will activate PTT function, activating the AUX_MIC input.
3
Fixed level (independent of volume level) received audio signal, including alert tones. Flat or de-emphasis are pro-
grammed by CPS. Output voltage is approximately 100 mVrms per 1kHz of deviation. The DC offset is 1.4V.
4
This output is used to detect when a rear microphone accessory is taken off-hook, to override PL to alert the user 
to busy traffic prior to transmitting.
5
This microphone signal is independent of the microphone signal on the front microphone connector. The nominal 
input level is 80mVrms for 60% deviation when used for motorcycle, but can also support 300 mVrms for future 
APCO accessories. The DC impedance is 660 ohms and the AC impedance is 560 ohms.
6
See Table 2-1 in Chapter 2 for wiring options.
Note: Please see the XPR 4300/4350/4500/4550 Basic Service manual (Motorola publication part number 
6816816H01) for more detailed descriptions of these pins. 
Table 3-1.  Rear Accessory Jack Pin Functions 
Pin 
No.
Pin Name Pin Function
Pin 
No.
Pin Name Pin Function
1 USB+ USB + (Data) 14 Rx Audio Receive Live Audio   3
2 USB- USB - (Data) 15 AUX Audio 2 PUBLIC Address 2
1
3 VBUS USB Power (5V from USB 
accessory/cable)
16 GND Ground
4 USB GND USB/APM Ground 17 GPS-1(PTT) 5V Level GPIO, PTT Input
2
5 APM2 One Wire Data 18 GND Ground
6 APM1 One Wire Data 19 GPS-2(Monitor) 5V Level GPIO, Monitor 
Input
7 SW B+ Switched Battery Voltage 20 GPS-6 5V Level GPIO
8 PWRGND Ground 21 GPS-3 5V Level GPIO, Channel 
Activity Function
9 SPKR- Speaker - (3.2 ohm minimum 
impedance)
22 GPS-7 5V Level GPIO
10 SPKR+ Speaker + (3.2 ohm 
minimum impedance)
23 EMERGENCY Emergency Switch Input   1
11 Tx Audio Rear External Microphone 
Input
5
24 GPS-7 5V Level GPIO
12 Audio GND Audio Ground 25 IGN SENSE Ignition Sense
6
13 AUX Audio 1  PUBLIC Address 1 26 VIP-1 12V Tolerant, 5V GPIO, 
External Alarm