Rockwell Automation 1403-NDNET DeviceNet Communications Card Installation Instructions - Manual (Page 23)

Publication 1403-IN054A-EN-P - August 2001
Product Description 1-17
I/O Messaging The Powermonitor II supports three types of I/O Messaging
•
Polled
•
Change of State (COS)
•
Cyclic
The default setting is 8 Rx and 4 Tx bytes; however, the I/O Message
is configurable up to 22 different parameters consisting of up to 64
words. These words can be retrieved from the DeviceNet scanner
using block transfer reads for the PLC-5 or accessing the M1 file or
input image table from the SLC-500. The poll type and polling rate is
configurable through RSNetWorx for DeviceNet.
Polled I/O Messaging
Polled I/O messaging allows the user to retrieve real-time power
parameters at updates rate up to 33 ms. The Powermonitor II supports
both Every Scan and Background Polled Messaging.
TIP
Change of State and Cyclic Messaging typically
reduces network bandwidth utilization compared to
Polled Messaging.