Rockwell Automation 1785-Lx0C15 ControlNet PLC-5 Programmable Controllers User Manual - Manual (Page 53)

1785-UM022C-EN-P - February 2008
Planning to Use Your ControlNet PLC-5 Processor 2-15
Using Multicast Outputs
To use multicast outputs, you must first configure each Multicast
Output connection in RSNetworx 3.0:
1. In the Details Tab of Connection Properties dialog, change the
Scanner to Target Network Connection to Multicast. You cannot
modify this field for any device that does not support multicast
outputs.
2. The Scanner to Target Multicast ID of the Details Tab indicates to
which multicast output group the connection belongs.
All connections with the same Multicast ID will have their output
data combined into a single transmission on the ControlNet
network.
The processor will combine the output data into a single packet
and simultaneously send it to all assigned connections that have
the same:
• Request Packet Interval
• Output Address in the PLC-5 data table
• Output Size
You must determine if the output data being sent to each device of
a multicast group is compatible with the application.
Using Multicast Outputs affects the ControlNet I/O Status file
Immediate Inhibit bit and ControlNet I/O Status file Reset bit
functionality:
• ControlNet I/O Status file Immediate Bit - since all
connections in a Scanner to Target Multicast ID group share the
same output data, the Immediate Inhibit Bit will not take affect
until all connections of that group have their immediate inhibit bit
set. After the immediate inhibit takes place, you may
independently re-enable each connection by clearing this bit.
• ControlNet I/O Status file Reset Bit - all connections of a
Scanner to Target Multicast ID group must have this bit set or
cleared so that the target devices are put into the correct state.
The Reset Bit affects all connections for a given multicast ID
group.