Rockwell Automation 2LW3000 LonWorks Communication Option Module for VTAC 7 Drives - Manual (Page 67)

Conditions Required for Operation 8-1
C
HAPTER
8
Conditions Required for Operation
This chapter describes the conditions required for performing some common actions
and how the combination of SNVTs and SCPTs affect the operation of the drive.
8.1 General Guidelines
• The LonWorks module and the drive must be installed and configured correctly.
Note the following VTAC 7 parameter settings:
• P.061 = 1. This enables the LonWorks module to have full access to all
parameters in the drive. The LonWorks module will fault the drive if this is not set
correctly.
• P.000 = OP. This enables the drive to accept frequency settings and/or start/stop
commands from the LonWorks module.
• P.028 = 100. This enables nvoDriveSpeed to show the correct percentage of
nominal speed. This is written by the LonWorks module at start up.
• NCIs (network configuration properties) are usually only written to the drive. NCI
values are read from the drive only at start up, when resetting faults, and when an
offline-to-online transition occurs. This is done to ensure consistency of parameters
values on both the LonWorks network and in the drive.
• The tune/cfg bit in the VTAC 7 command word will be set automatically by network
variables that have a parameter in the drive that require the tune/cfg bit to be set.
This will also cause all other tune/cfg parameters to be read by the drive. This is the
equivalent of setting nviObjRequest to RQ_PROGRAM.
8.2 Starting the Drive
The drive will output a frequency when all of the following conditions are met:
• nviDrvSpeedStpt.value is greater than zero
• nviDrvSpeedStpt.state is not equal to zero
• nviDrvSpeed Scale is not equal to zero
• RQ_ENABLE has been requested more recently than RQ_DISABLED
• The node is online