Allen-Bradley MicroLogix 1200 User Manual page 130

E-8 Connecting to Networks via RS-232 Interface
Publication 1762-UM001D-EN-P - March 2004
– 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 Number
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.
Setting Node Addresses
The best network performance occurs when node addresses are
assigned in sequential order. Initiators, such as personal computers,
should be assigned the lowest numbered addresses to minimize the
time required to initialize the network. The valid range for the
MicroLogix 1200 controllers is 1-31 (controllers cannot be node 0).
The default setting is 1. The node address is stored in the controller
Communications Status file (CS0:5/0 to CS0:5/7).