Chapter 4 programming the drive, 1 about controlnet network communication, Table 4.1 - network update time components – Rockwell Automation GV3000/SE AC Drive ControlNet Network Communication Board, M/N 2CN3000 User Manual
Page 63: Hapter, Programming the drive

Programming the Drive
4-1
C
HAPTER
4
Programming the Drive
This section describes how to program the drive over the ControlNet network.
4.1
About ControlNet Network Communication
The ControlNet network transports time-critical control information (e.g. drive
reference and feedback information) as well as non-time-critical information (e.g.
accessing drive parameters). The transportation of the non-time-critical information
does not interfere with the time-critical messages.
A node’s access to the network is controlled by a time-slice access algorithm, which
determines a node’s opportunity to transmit in each network update interval. You
configure how often the network update interval repeats by selecting a network update
time in milliseconds. The minimum network update time you can specify is 2 msec.
See table 4.1 below for more information about the components of the network update
time.
For optimum throughput, assign addresses to ControlNet nodes in a sequential order.
4.2
Configuring Drive Reference and Feedback Data as
Scheduled Transfers
This section describes how to:
•
configure scheduled traffic for the GV3000/SE drive
•
control the drive using the drive reference data
•
use scheduled drive feedback data
Table 4.1 – Network Update Time Components
This network update
time component
Allows:
scheduled
Information that is
time-critical (drive reference and
feedback) should be sent during this part of the NUT
interval.
unscheduled
Information that
can be delivered without time constraints
should be sent during this part of the NUT interval.
The amount of time available for the unscheduled portion is
determined by the traffic load of the scheduled portion.
During this part of the interval, nodes may have many or no
chances to transmit.