Rockwell Automation 1756-XXXX ControlLogix Analog I/O Modules - Manual (Page 25)

Publication 1756-UM009C-EN-P - December 2010 25
Analog I/O Operation in the ControlLogix System Chapter 2
Requested Packet Interval (RPI)
This configurable parameter also instructs the module to multicast its channel
and status data to the local chassis backplane.
The RPI, however, instructs the module to produce the current contents of its
on-board memory when the RPI expires, (that is, the module does not update
its channels prior to the multicast).
The module will reset the RPI timer each time an RTS is performed. This
operation dictates how and when the owner-controller in the local chassis will
receive updated channel data, depending on the values given to these
parameters.
If the RTS value is less than or equal to the RPI, each multicast of data from
the module will have updated channel information. In effect, the module is
only multicasting at the RTS rate.
On-Board Memory
Status Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Channel Data
Ch 0
Ch 1
Ch 2
Ch 3
Ch 4
Ch 5
Timestamp
41362
IMPORTANT
The RPI value is set during the initial module configuration by
using RSLogix 5000 software. This value can be adjusted when
the controller is in Program mode.