CM Baseplate Connectors
207
Appendix A
Pin-Outs for Cables and Connectors
RS-485 Pin-Outs
RS-485 Signal Descriptions
RS-485 signals are transmitted over a cable of twisted-pair-wires. The polarity of
the 2-to-6-Volt differential between the two wires indicates whether the data is
marking or spacing. If terminal A is negative with respect to terminal B, the line is
marking. If terminal A is positive with respect to terminal B, the line is spacing.
The maximum cable length is dependent on the wire used. For example, using 24-
AWG twisted-pair wire, the maximum length is 1.2 kilometers (4000 feet), but can
be extended using modems. The following table describes the RS-485 signals.
DB-9 Pin
Signal
Direction
RS-485 Function
1
—
—
—
2RD-A
In
Receive data
3
SD-A
Out
Transmit data
4
—
—
—
5
GND
—
Signal ground
6
—
—
—
7
SD-B
Out
Transmit data, invert
8
RD-B
In
Receive data, invert
9
OUT
Term
5 V DC through 1k
Ω
Housing
Shield
—
Safety ground
Signal
Designator
Description
Transmit Data
Transmit Data, Inverted
SD-A
SD-B
MP transmits serial data
Receive Data
Receive Data, Inverted
RD-A
RD-B
MP receives serial data
Signal Ground
GND
Signal ground
5 V DC through 1 K
Ω
Not used
Summary of Contents for Trident
Page 1: ...Trident Version 1 2 Triconex An Invensys Company Planning and Installation Guide ...
Page 10: ...x Contents Trident Planning and Installation Guide ...
Page 16: ...xvi Training Trident Planning and Installation Guide ...
Page 53: ...Main Processor Module 37 Chapter 3 System Description Model 2101 Main Processor Baseplate ...
Page 140: ...124 Covers Trident Planning and Installation Guide ...
Page 216: ...200 Replacing Modules Trident Planning and Installation Guide ...
Page 238: ...222 Diagread Cables and Debug Connectors Trident Planning and Installation Guide ...
Page 240: ...224 Trident Planning and Installation Guide ...
Page 248: ...232 Trident Planning and Installation Guide ...
Page 264: ...248 Glossary Trident Planning and Installation Guide ...
Page 274: ...258 Index Trident Planning and Installation Guide ...