Hand-off-auto – Rockwell Automation 20G PowerFlex 750-Series AC Drives User Manual
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Rockwell Automation Publication 750-RM002B-EN-P - September 2013
Chapter 1
Drive Configuration
A speed reference for Manual mode from a digital input can be set by selecting a
port in P328 [Alt Man Ref Sel]. This however causes all manual requests to use
that port as a reference, whether the request was from the digital input or from a
HIM. A separate manual reference port for use only when the request comes
from a digital input can be configured through P563 [DI ManRef Sel]. (To see
P564 [DI ManRef AnlgHi], set P301 [Access Level] to 1 “Advanced.”) If P328
[Alt Man Ref Sel] is configured, it overrides P563 [DI ManRef Sel] and provides
the manual reference.
If P563 [DI ManRef Sel] is an analog input, the maximum and minimum speeds
can be configured through P564 [DI ManRef AnlgHi] and P565 [DI ManRef
AnlgLo]. For analog input between the minimum and maximum, the drive
derives the speed from these parameters through linear interpolation.
Hand-Off-Auto
The Auto/Manual feature can be used in conjunction with a Hand-Off-Auto
Start to create a H-O-A switch that starts the drive and requests manual control
at the same time, allowing for a local speed reference to control the drive. See
for more details on the Hand-Off-Auto Start feature.
In the circuit below, a speed potentiometer was added to the analog input to
provide a speed reference to the drive. When the H-O-A switch is moved from
Auto to Hand, the digital input block requests manual control and issues a start
command to the drive. If the digital input port receives manual control, the drive
accelerates to the reference speed from the analog input. All attempts to change
the speed except from the analog input are blocked. If the drive is stopped while
in Hand, switch the H-O-A switch to Off and then back to Hand to restart the
drive.
If another port has manual control of the drive, but does not have exclusive
ownership of the logic commands (due to P326 [Manual Cmd Mask]), turning
the switch to Hand causes the drive to begin moving but for the analog input to
have no control over the speed.
+24V
+10V
H
A
O
XOO
OOX
XOO
DI 0: Stop
DI 1: HOA Start and
Manual Control
Analog IN 0: DI Manual
Speed Reference
Speed Potentiometer