Rockwell Automation 1764-xxxx MICROLOGIX 1500 PROGRAMMABLE CONTROLLERS - Manual (Page 142)

Publication 1764-UM001B-EN-P - April 2002
E-10 Understanding Communication Protocols
interference. If you route the cable through conduit, follow
these additional recommendations:
– Use ferromagnetic conduit near critical sources of electrical
interference. You can use aluminum conduit in non-critical
areas.
– Use plastic connectors to couple between aluminum and
ferromagnetic conduit. Make an electrical connection around
the plastic connector (use pipe clamps and the heavy gauge
wire or wire braid) to hold both sections at the same
potential.
– Ground the entire length of conduit by attaching it to the
building earth ground.
– Do not let the conduit touch the plug on the cable.
– Arrange the cables loosely within the conduit. The conduit
should contain only serial communication cables.
– Install the conduit so that it meets all applicable codes and
environmental specifications.
For more information on planning cable routes, see Industrial
Automation Wiring and Grounding Guidelines, publication 1770-4.1.
Software Considerations
Software considerations include the configuration of the network and
the parameters that can be set to the specific requirements of the
network. The following are major configuration factors that have a
significant effect on network performance:
•
number of nodes on the network
•
addresses of those nodes
•
baud rate
The following sections explain network considerations and describe
ways to select parameters for optimum network performance (speed).
See your programming software’s user manual for more information.
Number of Nodes
The number of nodes on the network directly affects the data transfer
time between nodes. Unnecessary nodes (such as a second
programming terminal that is not being used) slow the data transfer
rate. The maximum number of nodes on the network is 32.