Auto/manual examples – Rockwell Automation 20P PowerFlex Digital DC Drive User Manual
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Rockwell Automation Publication 20P-UM001I-EN-P - February 2013
281
Application Notes
Appendix C
Auto/Manual Examples
PLC = Auto, HIM = Manual
A process is run by a PLC when in Auto mode and requires manual control from
the HIM during set-up. The speed reference is issued by the PLC through a
communications module installed in the drive (Port 5). Therefore, parameter
1327 [DPI P5 Select] is set to “Speed Ref A” with the drive running from the
Auto source.
Acquire Manual Control
•
Press ALT then Auto/Man on the HIM. When the HIM acquires manual
control, the drive speed command comes from the HIM speed control
keys.
Release to Auto Control
•
Press ALT then Auto/Man on the HIM again. When the HIM releases
manual control, the drive speed command returns to the PLC.
PLC = Auto, Terminal Block = Manual
A process is run by a PLC when in Auto mode and requires manual control from
an analog potentiometer wired to the drive terminal block. The auto speed
reference is issued by the PLC through a communications module installed in the
drive (Port 5). Therefore, parameter 1327 [DPI P5 Select] is set to “Speed Ref A”
with the drive running from the Auto source. Since the Manual speed reference is
issued by analog input 2, parameter 75 [Anlg in2 Sel] is set to “TB Man Ref ”.
The value of analog input 2 can be viewed in parameter 267 [TB Manual Ref ].
To switch between Auto and Manual, parameter 136 [Digital In4 Sel] is set to
“Auto/ Manual”.
Acquire Manual Control
•
Close the digital input. With the input closed, the speed command comes
from the pot.
Release to Auto Control
•
Open the digital input. With the input open, the speed command returns
to the PLC.
Auto/Manual Notes
1.
Manual control is exclusive. If a HIM or Terminal Block takes manual
control, no other device can take manual control until the controlling
device releases control.
2.
If a HIM has manual control and power is removed from the drive, the
drive will return to Auto mode when power is reapplied.