User manual

eElectro Industries/GaugeTech Doc # E113-7-03-1.18 1-6

1.3: RS232 Wiring Details1.3: RS232 Wiring Details

RS232 communication is capable for a distance up to 50 feet (15.2 m). The Master Port and Slave

Ports 3–16 are 9-pin female RS232 ports. Use standard RS232 extension cables for all RS232

connections.

The RS232 Master Port enables the Substation Multiplexor to communicate directly with a computer

or connect to an external modem. The Master Port is DCE or DTE selectable. Set the switch beneath

the port to:

• DTE when using a modem (internal or external).

• DCE when connecting the Substation Multiplexor directly to a computer.

RS232 Female PortRS232 Female Port

Slave Ports 3–16 are DTE configured. When connecting an RS232 Slave Port to another DTE

device, use a Null Modem to reverse the Rx and Tx pins, as shown below:

RS232 Slave Port Pin

Assignments

PIN DTE

1 N/A

2 Rx

3 Tx

4 DTR

5 Gnd

6 DSR

7 RTS

8 CTS

9 N/A

RS232 Master Port

Pin Assignments

PIN DTE DCE

1 DCD DCD

2 Rx Tx

3 Tx Rx

4 DTR DSR

5 Gnd Gnd

6 DSR DTR

7 RTS CTS

8 CTS RTS

9 Ring Ring

Shorted Internally