Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 170)

170 Publication 1753-UM001C-EN-P - March 2010
Chapter 16 Peer-to-peer Communication Overview
Peer-to-Peer Profile II: Fast & Noisy
This profile provides fast data throughput for applications that require
fast data update rates. It is good for applications that require the
shortest feasible Worst-Case Reaction Time where minor loss of
messages can be corrected.
Fast & Noisy Characteristics
Minimum Ethernet
network
requirements
Fast
100 Mbit technology (100 Base TX), if HH
network profile Fast & Cleanroom is selected.
10 Mbit technology (10 Base T), if HH network
profile Medium & Cleanroom is selected.
Switched
Fast Ethernet (full duplex recommended) LAN
switches, if HH network profile Fast &
Cleanroom is selected.
10 MBit hubs, if HH network profile Medium &
Cleanroom is selected.
Or use switches integrated into the
GuardPLC 1600/1800 controllers.
Noisy
Low probability for loss of messages.
Time for
≥
1 repetitions.
Characteristics of the
communication path Minimum delays
ResponseTime
≤
ReceiveTMO
÷
2 (otherwise ERROR)
Variables
ResponseTime manually set in the Peer-to-Peer Editor
ReceiveTMO manually set in the Peer-to-Peer Editor
WDZ manually set in the controller properties
Suitable HH network
profile Fast
Medium (
≤
10 controllers in a Token Group)
Peer-to-Peer
parameter presets
•
QueueLen = 2
•
Communication Time Slice large enough to process and send
all data defined for transmission in one CPU cycle.
•
ResendTMO
– if ReceiveTMO
≥
2 x WDZ, then
ResendTMO = ResponseTime (
≥
1 Resend possible)
– if ReceiveTMO < 2 x WDZ, then ERROR
•
AckTMO = 0
•
ProdRate = 0