Ercogener GenPro 25e, Руководство пользователя

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Descriptions and non-contractual illustrations in this document are given as an indication only.
ERCOGENER reserves the right to make any modification.
Dct_427_02
3.7 Serial link RS232C
The RS232 interface makes an adaptation of the voltage levels between the GSM/GPRS module (DCE) and
the communication port of a PC (DTE).
Table 25 : Pins description of RS232C interface
Circuit - V24 - RS232C
Connector
SubD HD 15 points
Pins number
I/O Description
109
– DS – DCD
1 O Data Carrier Detect
103
– ED – TXD
2 I Transmit serial data
104
– RD – RXD
6 O Receive serial data
107
– PDP – DSR
7 O Data Set Ready
108/2
– TDP – DTR
8 I Data Terminal Ready
102
– TS – GND
9 Ground
106
– PAE – CTS
11 O Clear To Send
105
– DPE – RTS
12 I Request To Send
125
– IA – RI
13 O Ring Indicator
Table 26 : Characteristics of RS232C serial link
Characteristics Symbols Conditions Min. Typ. Max. Unit
Input Voltage
– Range
V
INPUT
Input Voltage
– Range
-25 +25 V
DC
Input Voltage
– Low
V
IL
Input Voltage
– Low
0.4 1.3 V
DC
Input Voltage
– High
V
IH
Input Voltage
– High
2 24 V
DC
Input Hysteresis V
Hys
Input Hysteresis 0.14 V
DC
Input Resistance R
in
Input Resistance 3 5 7
KΩ
Output Voltage ±5 ±6.4 V
DC
Transmitter Output
Resistance
V
OUT
All transmitter outputs
loaded with 3 kΩ to
ground
300
Ω
RS-232 Output Short-Circuit
Current
I
CC
±15 ±60 mA
Figure 14 : Normalized signals of a RS232C serial link