Rockwell Automation 1766-Lxxxx MicroLogix 1400 Programmable Controllers User Manual - Manual (Page 229)

Rockwell Automation Publication 1766-UM001H-EN-P - May 2014 189
Connecting to Networks via RS-232/RS-485 Interface Appendix E
Important DH-485 Network Planning Considerations
Carefully plan your network configuration before installing any hardware. Some
of the factors that can affect system performance are:
• amount of electrical noise, temperature, and humidity in the network
environment.
• number of devices on the network.
• connection and grounding quality in installation.
• amount of communication traffic on the network.
• type of process being controlled.
• network configuration.
The major hardware and software issues you need to resolve before installing a
network are discussed in the following sections.
Hardware Considerations
You need to decide the length of the communication cable, where you route it,
and how to protect it from the environment where it will be installed.
When the communication cable is installed, you need to know how many devices
are to be connected during installation and how many devices will be added in the
future. The following sections help you understand and plan the network.
Number of Devices and Length of Communication Cable
The maximum length of the communication cable is 1219 m (4000 ft). This is
the total cable distance from the first node to the last node in a segment.
However, two segments can be used to extend the DH-485 network to 2438 m
1746-BAS BASIC Module SLC Chassis Provides an interface for SLC 500 devices to foreign devices. Program in
BASIC to interface the 3 channels (2 RS232 and 1 DH-485) to printers,
modems, or the DH-485 network for data collection. 1746-UM004
1746-PM001
1746-RM001
2760-RB Flexible Interface
Module (1771) PLC Chassis Provides an interface for SLC 500 (using protocol cartridge 2760-SFC3) to
other A-B PLCs and devices. Three configurable channels are available to
interface with Bar Code, Vision, RF, Dataliner™, and PLC systems.
1747-6.12
2760-ND001
1784-PKTX,
-PKTXD PC DH-485 IM PCI Computer Bus Provides DH-485 using RSLinx. 1784-6.5.22
1784-PCMK PCMCIA IM PCMCIA slot in
computer Provides DH-485 using RSLinx. 1784-UM519
2711-K5A2,
-B5A2, -K5A5,
-B5A5, -K5A1,
-B5A1, -K9A2,
-T9A2, -K9A5,
-T9A5, -K9A1,
and -T9A1 PanelView 550
and PanelView
900 Operator
Terminals Panel Mount Provides electronic operator interface for SLC 500 processors. 2711-UM014
Devices that Support DH-45 Network
Catalog
Number Description Installation Function Publication