GSM100 USERS MANUAL
1.2.3. 15-PIN D-SUB Female connector (RS232 / Audio)
The connector provides serial link and audio link to the modem.
-
Pin number
Name
DCD
TX
BOOT
EIA designation
Data Carrier Detect
Transmit Data
Type
Output
Input
Note
1
2
3
Input
Not used
4
5
6
7
8
9
10
11
12
13
14
15
MICROPHONE (+)
MICROPHONE (-)
RX
Input
Input
Receive Data
Data Set Ready
Data Terminal Ready
Ground
Output
Output
Input
Ground
Output
Output
Input
Output
Input
Output
DSR
DTR
GND
SPEAKER(+)
CTS
RTS
RI
RESET
SPEAKER(-)
Clear to Send
Request to Send
Ring Indicator
Pull low to reset
Specification of microphone and speaker to be connected :
Parameters
Min
Typical
Max
Remark
Microphone current @2V / 2K Ohm
Microphone input level
0.5 mA
100
mVpp
Speaker output current 150 Ohm/
1nF
16mA
Speaker impedance
32ohm
Please refer to the document “Application notes - Power supply & Audio” for more information of audio connection.
1.2.4. 4-PIN modem socket (Power, Input / Output)
Pin assignment of 4-pin connector
Pin number
1
2
Name
I/O
~INTR
Functions
Input / Output port
Interrupt function triggered by pulling this pin to
ground or LOW level; reserved for additional
functions with new firmware
DC power negative input
3
4
POWER -
POWER +
DC power positive input
DS020-7 Oct ‘06
©2006 REG No 277 4001, ENGLAND.
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