Rs232 Interface - MTX -3G-JAVA series User Manual

4.4.2 RS232 interface
The modem supports a standard RS232 4‐wire serial interface (EIA/TIA 574) via its 15 pin Sub‐D
connector, shown below. This interface is connected to the ASC0 port using a level shifter converter,
except on the base MTX‐3G‐JAVA and MTX‐3G‐JAVA‐ULP, which use an ASC1 port instead of ASC0.
The MTX‐3G‐JAVA modem is designed to be used as a DCE (data circuit‐terminating equipment).
Based on the conventions for DCE‐DTE connections, it communicates with the customer application
(DTE‐ data terminating equipment) using the following signals:
• Port TxD @ application sends data to MTX‐3G‐JAVA Terminal's TD.
• Port RxD @ application receives data from MTX‐3G‐JAVA Terminal's RD.
The RS‐232 interface is implemented as a serial asynchronous transmitter and receiver conforming to
ITU‐T V.24 Interchange Circuits DCE. It is configured for 8 data bits, no parity and 1 stop bit and can
be operated at fixed bit rates from 300bps to 460.8kbps.
Autobauding supports bit rates from 1.2kbps to 460.8kbps. Hardware handshake using the /RTS and
/CTS signals and XON/XOFF software flow control are supported.
The electrical characteristics of the serial port signals are shown below:
Signal
RD0
TD0
GND
RTS
CTS
Features (ASC1)

Includes data lines TD1 and RD1 (2‐wire/4‐wire)

Includes the status lines RTS0 and CTS0 and supports hardware flow control (4‐wire only)

On ASC1 no RING line is available. The indication of URCs on the second interface depends on
the settings made with the AT^SCFG command.

Configured for 8 data bits, no parity and 1 or 2 stop bits.

ASC1 can be operated at fixed bit rates from 1200 bps to 921600 bps. Autobauding is not
supported on ASC1.
www.mtx‐terminals.com
Direction Description
Output Received data
Input Transmitted data
‐ Ground connection
Input Request to send
Output Clear to send
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MTX M2M® by MATRIX ELECTRONICA S.L.U
MTX‐3G‐JAVA Family
2015/10 v1.6
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