Rockwell Automation 20B PowerFlex 700 AC Drives Vector Control (v4.001 and up) - Manual (Page 103)

Rockwell Automation Publication 20B-UM002G-EN-P - July 2014 103
HIM Overview Appendix B
Disconnecting the HIM
In drive Firmware Revision 9.001 and later, the user can configure the drive to
continue operating at a defined speed reference if a HIM DPI Port 1-3 loss
occurs, which is indicated by bits 21, 22, and 23 in read-only parameter 211
[Drive Alarm 1]. These three ports can be configured independently. Using this
feature will allow the drive to operate at the speed defined in parameter 173 [DPI
Loss Action], and indicate a DPI Port x Loss as configured in parameter 238
[Fault Config 1] and parameter 259 [Alarm Config 1]. If the HIM was supplying
the speed reference when removed, the drive speed reference cannot be adjusted
from any other source while the HIM is disconnected.
If the present speed reference was not from the DPI port that was disconnected,
the drive speed will continue to be commanded by that reference.
If the drive stops while the HIM is disconnected and the DPI Port x loss is
activated, the last commanded HIM speed reference will be saved in the drive.
When the user issues a start command, the last commanded HIM speed reference
will be used.
In the default condition, a DPI loss fault will occur if a HIM is disconnected. To
avoid or override a DPI loss fault and keep the drive running:
1. Set parameter 173 [DPI Loss Action] to “1” (Hold OutFreq) or “2” (Goto
Preset1).
2. Change the respective bit that corresponds to the DPI port (bits 16…18)
in parameter 238 [Fault Config 1] to a value of “0” to disable the fault.
3. Verify that the respective bit that corresponds to the DPI port (bits
21…23) in parameter 259 [Alarm Config 1] is in its default state of “1”
(condition true).
Reconnecting the HIM
When the HIM is reconnected to the original DPI port, the drive speed
reference will be transferred to the HIM, providing a constant drive speed while
the HIM regains control of the speed reference. Once communication between
the drive and HIM is re-established, the DPI Port x Loss alarm will clear and the
HIM will control the speed reference.
IMPORTANT When using parameter 173 [DPI Loss Action], the user must make certain that
the HIM is not the sole stopping source. The user must verify that an alternate
stop source is available. If the HIM is the sole stopping source and it is
disconnected, the drive will fault regardless of the configuration in parameter
238 [Fault Config 1].