Rockwell Automation Logix5000 Controllers Produced and Consumed Tags Programming Manual - Manual (Page 37)

Produce a Large Array Chapter 2
• Fewer connections are used than if you broke the data into multiple arrays
and sent each as a produced tag. For example, an array with 5000 elements
would take 40 connections (5000/125=40) by using individual arrays.
• Faster transmission times are achieved than if you used a message
instruction to send the entire array.
•
Messages are unscheduled and are executed only during the ‘system
overhead’ portion of the Logix5550 execution. Therefore, messages can
take a fairly long time to complete the data transfer.
• You can improve the transfer time by increasing the system overhead
time slice, but this diminishes the performance of the continuous task.
Rockwell Automation Publication 1756-PM011F-EN-P - October 2014 37