Rockwell Automation 56AMXN/B ControlLogix AutoMax Comm Module - Manual (Page 24)

Page 24 AutoMax DCSNet /RE RIO Module
Publication number 56AMXN-UM002A-EN-P November 2002
4. Assign the module a Name and optionally a Description.
5. Set the Slot to match the slot number of the module in the chassis.
6. Select a Comm Format from the list. Select a master or slave
connection.
Choose a Comm Format that is large enough for the anticipated number
of drops on the network. Too small means you can’t map all the data;
too large and you add extra traffic to the backplane. It’s the number of
drops that matters, not the drop numbers, since you map the drop data
tags. For example, if the 56AMXN is a DCS master and the network
contains only drops 1 and 55, these two drops can be mapped using
Comm Format Master – 07 Drops by writing the appropriate values to
the configuration tag for the module.
To change the Comm Format, you must delete the old module and add a
new one with the required size. Any configuration data you’ve entered is
lost when you delete the old module, so if you anticipate the DCS
network will be larger in future, it’s best to select a Comm Format that
allows room for the data in the future network.
7. Click Next > to display the second Module Properties – Local
(56AMXN 2.1) dialog box (same as the Connection Tab in Module
Properties)
Figure 5 Module Properties Dialog 2
8. Set the module RPI. This is how often the module’s scheduled data
is updated in the processor. The value can range from 3.0 to 750 ms.
The default is 3 ms.