Rockwell Automation 1756-IF4FXOF2F ControlLogix High-speed Analog I/O Module - Manual (Page 19)

Rockwell Automation Publication 1756-UM005B-EN-P - January 2013 19
High-speed Analog I/O Operation in the ControlLogix System Chapter 2
Requested Packet Interval (RPI)
The RPI is a configurable parameter that also instructs the module to multicast
its channel and status data to the local chassis backplane. However, the RPI
instructs the module to multicast the current contents of its on-board memory,
including input and output data echo, when the RPI expires. When the RPI
expires, the module does not update its channels prior to the multicast. The RPI
also instructs the owner-controller to update the module outputs.
IMPORTANT The owner-controller sends output data to the high-speed analog I/O module
outputs asynchronously to when channel data and output data echo data are
returned over the ControlLogix backplane.
The RPI value is set during the initial module configuration. Adjusting the RPI
causes the connection to close and reopen.
On-Board Memory
Status Data
Channel Data
Channel Data
Channel Data
Channel Data
Timestamp
Output Data Echo
Output Data Echo
Input 0
Input 1
Input 2
Input 3
Output 0
Output 1