Rockwell Automation 1786-series ControlNet Fiber Media Planning and Installation Guide - Manual (Page 25)

Rockwell Automation Publication CNET-IN001C-EN-P - October 2011 25
Get Started with the ControlNet Network Fiber Media System Chapter 1
A fiber-optic ring may contain up to 20 1786-RPFRL/B (long distance) or
1786-RPFRXL/B (extra-long distance) fiber repeaters, depending on
the application.
Configure the Media in
RSNetWorx for ControlNet
Software You can use RSNetWorx for ControlNet software to determine whether or not
your system meets the network parameter requirements. Based on your system
planned requirements (NUT, SMAX, UMAX, types and length of cable,
number and types of repeaters and worst case network delay), RSNetWorx
software will verify the network configuration parameters.
If RSNetWorx is unable to schedule the network due to errors, make the
necessary changes. Changes might include inserting the correct media lengths
and number of repeaters or increasing RPI, so the software can calculate the
correct network parameters and download them to the keeper.
Set up the Network SMAX Parameter in RSNetWorx Software
You must properly set up the SMAX parameter in RSNetWorx for ControlNet
software when used with the 1786-RPFRL or 1786-RPFRXL repeater module.
The SMAX parameter sets the maximum scheduled node address on a
ControlNet network. Refer to the documentation supplied with the RSNetWorx
for ControlNet software.
You must set the SMAX parameter at least one node number higher than the
highest-used scheduled node number. For example, on a network with 49
scheduled nodes (with 49 being the highest-used scheduled node number), you
must set SMAX to at least 50. In this example, node number 50 is an unused
scheduled node number.
For more information, see Getting Results with RSNetWorx for ControlNet,
publication
CNET-GR001 .
IMPORTANT When used in a ring topology, redundant coaxial cabling (linear bus) or
redundant rings are not allowed. Due to timing differences, the
1786-RPFRXL/B and 1786-RPFRL/B fiber modules do not support
redundant rings.
IMPORTANT When setting the SMAX parameter, you must allow one unused
scheduled node address. This unused node address must be the highest
available scheduled node number. Therefore, the maximum usable node
address when using the 1786-RPFRL/B or 1786-RPFRXL/B module is 98.