Rockwell Automation 1755-OF8 GuardPLC Controller Systems - Manual (Page 161)

Publication 1753-UM001C-EN-P - March 2010 161
Peer-to-peer Communication Overview Chapter 16
The Worst-case ReactionTime T
R
is process-dependent and has to be
coordinated with the approving board. In the Peer-to-Peer Editor, the
Worst-case ReactionTime can be read in the Worst Case column.
HH Network Profiles Two HH network profiles are used to configure the appropriate set of
parameters for the network in use. The profiles, described below, can
be chosen in the properties of the HH Network token group.
•
Profile I: Fast
•
Profile II: Medium
A third profile option, None, lets you set parameters manually. See
The None Profile on page 167 for more information.
Profile I: Fast
This is the recommended profile. It provides the fastest data
throughput, and covers approximately 95% of all application cases.
Use Fast for:
•
applications that require fast data update rates within a token
group
(1)
.
•
fast communication between two or more token groups
(1)
,
where the other token groups must run Fast as well.
•
applications that require the shortest feasible Worst-case
Reaction Time.
(1) A token group consists of at least two controllers, which share the same token. Each controller must be a
member of exactly one token group. A token group can work stand-alone or can exchange data with other token
groups.
TIP
Because Token Passing is switched off in the Fast profile, it is
possible to generate a token group with only one controller. No
second controller is needed to exchange the token. The single
controller can communicate with other token groups containing
more controllers.