INSTALLATION
Pin
Function
1
Audio +
2
Not Connected
3
BUS+
4
Audio-
5
Not Connected
6
Ground
7
Radio On/Off Control
8
SCI_TX
9
FLT_A+
10
Analog Ground
25-Pin subD Connector
Data Expansion Head Enhanced:
Pin
Function
1
GND
2
RS232_SCI_TX
3
RS232_SCI_RX
4
RS232_RTS
5
RS232_CTS
6
FLT_A+
7
Signal_GND
9
NC
10
NC
11
NC
12
SW_B+
13
MTM5400 Mobile Terminal Installation Manual
Table 10 10-Pin TELCO Connector
Balanced Audio + (Bidirectional)
This is used for communication between the radio and an Enhanced Control Head.
Balanced Audio - (Bidirectional)
Ground
This is the Enhanced Control Head service request input. A level of 5 volts
indicates that the Enhanced Control Head needs to communicate with the radio. In
addition it switches on the radio's voltage regulators. The idle state is a level below
0.6V.
This if for communication between the radio and the Enhanced Control Head.
This voltage is at battery voltage level and is available as long as the radio is
connected to the supply voltage. The maximum current is 300mA. A fuse in the
radio prevents further circuit damage in case of shorting this pin to ground.
Analog Ground
Table 11 25-Pin subD Connector
Ground
Transceive data (RS232 line with RS232 level)
Receive data (RS232 line with RS232 level)
Request to Send (RS232 line with RS232 level)
Clear to Send (RS232 line with RS232 level)
Filtered unswitched U
Ground for RS232
Not Connected
Not Connected
Not Connected
Switched U
+/100mA
B
Description
Description
+ / 200mA
B
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