Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 169)

Publication 1753-UM001C-EN-P - March 2010 169
Peer-to-peer Communication Overview Chapter 16
Peer-to-Peer Profile I: Fast & Cleanroom
This profile provides the fastest data throughput for applications that
require fast data update rates. It is also best for applications that
require the shortest feasible Worst-Case ReactionTime.
Fast & Cleanrooom Characteristics
Minimum Ethernet
network
requirements
(1)
(1) The network can be shared with other applications, if sufficient bandwidth is provided.
Fast 100 Mbit technology (100 Base TX)
Switched
Fast Ethernet (full-duplex recommended) LAN
switches or integrated switches
(GuardPLC 1600/1800 controller) required.
Cleanroom
No loss of data due to traffic overload, harsh
environmental conditions or network defects.
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
(Watchdog
Time) manually set in the controller properties
Suitable HH network
profile Fast
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 = ReceiveTMO
÷
2
,
or
ResendTMO = ResponseTime, whichever is greater
– if ReceiveTMO < 2 x WDZ, then
ResendTMO = ReceiveTMO
•
AckTMO = 0
•
ProdRate = 0