Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual - Manual (Page 40)

Placing System Hardware
Chapter 3
3-5
To plan a raceway layout, do the following:
categorize conductor cables
route conductor cables
Categorize Conductors
Segregate all wires and cables into categories as described in the Industrial
Automation Wiring and Grounding Guidelines, publication 1770-4.1. See
the installation data for each I/O module that you are using for information
about its classification.
Route Conductors
To guard against coupling noise from one conductor to another, follow the
general guidelines for routing cables described in the Industrial
Automation Wiring and Grounding Guidelines, publication 1770-4.1. You
should follow the safe grounding and wiring practices called out in the
National Electrical Code (NEC, published by the National Fire Protection
Association, in Quincy, Massachusetts), and local electrical codes.
DH+ Link Cabling
At a DH+ transmission rate of 57.6 kbps, do not exceed 3,048 cable-m
(10,000 cable-ft) for a trunkline cable length or 30.5 cable-m (100 cable-ft)
for a dropline cable length.
Remote I/O Link Cabling
Refer to Table 3.B for remote I/O link trunkline cable length restrictions.
Table 3.B
Maximum Cable Lengths per Communication Rate
Transmission Rate Maximum Cable Length
57.6 kbps 3,048 m (10,000 ft)
115.2 kbps 1,524 m (5000 ft)
230.4 kbps 762 m (2500 ft)
Important: All devices on the remote I/O link must be communicating at
the same transmission rate.
Planning Cabling