Db9 Connector: 8-Wire Rs232 Port - MTX -3G-JAVA-IoT User Manual

4.3 DB9 connector: 8-wire RS232 port

The STD and DB9 models support a standard RS232 8-wire serial interface (EIA/TIA 574) via its 9 pin
Sub-D connector, shown below.
Port signals are connected to an internal coprocessor through a transceiver. In the STD model, which
has two RS232 and a RS485 port, this coprocessor selects which of those ports are connected to the
Cinterion GSM engine's UARTs ASC0 and ASC1. Users can select the ports configuring the device's DIP
switches. Please read section 4.7
your choice.
The MTX-IoT 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 TXD of MTX-IoT Terminal
•
Port RxD @ application receives data from RXD of MTX-IoT Terminal
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 1200bps to 921600bps.
The DB9 connector pinout is shown in the table below:
www.mtxm2m.com
to learn how to configure DIP switches in order to select the port of
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