GSM100 U
SERS
M
ANUAL
1.2.3.
15-PIN D-SUB Female connector (RS232 / Audio)
-
The connector provides serial link and audio link to the modem.
Pin number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Name
DCD
TX
BOOT
MICROPHONE (+)
MICROPHONE (-)
RX
DSR
DTR
GND
SPEAKER(+)
CTS
RTS
RI
RESET
SPEAKER(-)
EIA designation
Data Carrier Detect
Transmit Data
Receive Data
Data Set Ready
Data Terminal Ready
Ground
Clear to Send
Request to Send
Ring Indicator
Type
Output
Input
Input
Input
Input
Output
Output
Input
Ground
Output
Output
Input
Output
Input
Output
Note
Not used
Pull low to reset
Specification of microphone and speaker to be connected :
Parameters
Microphone current @2V / 2K Ohm
Microphone input level
Min
Typical
0.5 mA
Max
100
mVpp
Remark
Speaker output current 150 Ohm/
16mA
1nF
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
DC power positive input
3
4
POWER -
POWER +
DS020-7 Oct ‘06
©2006
REG No 277 4001, ENGLAND.
Page 6