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TRM282 RS232 Interface

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Main Page > TRM Modems > TRM282 > TRM282 Manual > TRM282 RS232 Interface

Summary

TRM282 has 1 x DB9 connector and supports RS232 (with RTS, CTS flow control). For TRM142 pinout, please refer to QSG page.

RS232 Connector pinout


The following table lists commonly used RS-232 signals (DTE male to DCE female). The RS232 connector type on device is a DCE female.

PIN NAME* DESCRIPTION* DIRECTION ON THIS DEVICE
1 DCD Data Carrier Detect Output
2 RXD Receive Data Output
3 TXD Transmit Data Input
4 DTR Data Terminal Ready Input
5 GND Signal Ground -
6 DSR Data Set Ready Output
7 RTS Ready To Send Input
8 CTS Clear To Send Output
9 RI Ring Indicator Output (connected to +3.8V permanently via a 4.7k resistor)

Cables


There are two types of RS232 serial devices: DTE and DCE. DTE typically refers to the serial port on a PC or terminal, while DCE refers to communication devices. Connectors mounted on DTE are likely to be male, and those mounted on DCE are likely to be female.

This device is DCE and has a female connector.


To connect a standard DTE device, use a straight-through Female/Male RS232 cable:

See "straight-through" cable pinout below:


To connect another DCE device to RUT/TRB, a Null-modem or "crossover" Male/Male cable should be used:

See "crossover" cable pinout below:


Maximum cable length is 15 meters or the cable length equal to a capacitance of 2500 pF (for a 19200 baud rate). Using lower capacitance cables can increase the distance. Reducing communication speed can also increase maximum cable length.