User guide
Table Of Contents
- Presentation
- Warning
- Copyright
- 1 References
- 2 Packaging
- 3 General presentation
- 4 Characteristics and Services
- 5 Use of the modem
- 5.1 Starting with the modem
- 5.2 Specific recommendations for the use of the modem in vehicles
- 5.3 GSM led of the modem
- 5.4 Echo function of AT commands deactivated
- 5.5 Checking the quality of the GSM reception signal
- 5.6 Verification of PIN code
- 5.7 Verification of modem registration on GSM network
- 5.8 Verification of modem registration on GPRS network
- 5.9 Verification of internal voltages of the modem
- 5.10 Main AT commands (HAYES)
- 5.11 Turning OFF the modem
- 5.12 Updating procedure of the modem
- 6 Trouble Shooting
- 7 Functional description
- 8 Technical characteristics
- 8.1 Mechanical characteristics
- 8.2 Electrical characteristics
- 8.3 Environmental characteristics
- 8.4 Standards/Conformities
- 9 Security recommendations
- 10 Recommended accessories
- 11 Client support
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Descriptions and non-contractual illustrations in this document are given as an indication only.
ERCO & GENER reserves the right to make any modification.
Dct_427_01
Figure 19 : Normalized signals of a RS232 serial link
The RS232 interface was designed to allow certain flexibility in the use of the serial interface signals. In fact,
after the setting (see command AT+IFC), the modem can work in 3-wire mode (using only the signals TX,
RX, GND), but the use of the signals TX, RX, GND, CTS, RTS is required for a GPRS application, which is
not the case for the signals DTR, DSR, DCD and RI which may not be used.
7.3.2 Pins description
Table 20 : Pins description of RS232 interface
Signal
Connector Sub HD
Pin N°
I/O
RS232
Standards
Description
CTXD/CT103 2 I TX Transmit serial data
CRXD/CT104 6 O RX Receive serial data
CRTS/CT105 12 I RTS Request To Send
CCTS/CT106 11 O CTS Clear To Send
CDSR/CT107 7 O DSR Data Set Ready
CDTR/CT108-2 8 I DTR
Data Terminal
Ready
CDCD/CT109 1 O DCD
CRI/CT125 13 O RI
CT102/GND 9 Ground