TRM142 RS232 Interface
Summary
TRM142 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 | Input |
| 2 | RXD | Receive Data | Input |
| 3 | TXD | Transmit Data | Output |
| 4 | DTR | Data Terminal Ready | Output |
| 5 | GND | Signal Ground | - |
| 6 | DSR | Data Set Ready | Input |
| 7 | RTS | Ready To Send | Output |
| 8 | CTS | Clear To Send | Input |
| 9 | RI | Ring Indicator | Input (connected to +3.8V permanently via a 4.7k resistor) |
| 9 | RI | Ring Indicator | Input (connected to +5V 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 cable pinout below:
To connect another DCE device to RUT/TRB, a Null-modem (crossed) Male/Male cable should be used:
See straight crossed 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.