Bradley Smoker PLC-5 Communicating with Devices on a Serial Link, Choosing Between, RS-423

Chapter 10

Communicating with Devices on a Serial Link

Using This Chapter

For Information About:	Go to Page:
Choosing between RS-232C, RS-422A, and RS-423	10-1
Configuring the controller serial port	10-2
Using channel 0	10-2
Cabling	10-5
Configuring channel 0	10-6
Monitoring channel 0 status	10-22

Choosing Between

RS-232C, RS-422A, and

RS-423

If you are using PLC-5 controllers in Supervisory Control and Data Acquisition (SCADA) applications, see the SCADA System Selection Guide, publication AG-SG001.

The table below summarizes some of the differences between RS-232C, RS-422A, and RS-423 communication modes:

This	Is Normally Used When You
Method
RS-232C	have a data transmission range of up to 50 ft. (15.2m).
	Applications requiring longer distances can use modems or line drivers.
	Use RS-232C for half- or full-duplex communication. For example, computers
	communicating with controllers or modems in SCADA applications.
RS-422A	want to transmit data to RS-422A-compatible devices over ranges greater than
	RS-232C allows. See on page 10-5.
	Use RS-422A for point-to-point communication, with one device communicating with
	as many as 10 other devices.
RS-423	want to transmit data to RS-423-compatible devices over ranges greater than
	RS-232C allows. See on page 10-5.

Use RS-423 for point-to-point communication, with one device communicating with as many as 10 other devices.

Publication 1785-UM012D-EN-P - July 2005