Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual - Manual (Page 151)

Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013 151
Detail Drive Configuration and Operation Chapter 1
5. Setting the speed change detection level in parameter 224 [TachSwitch
Level].
6. Setting parameter 153 [Control Options] bit 16 “Auto Tach Sw” to 1 for
automatic switch over.
7. Setting parameter 510 [FVC Mode Config] bit 22 “SrLssRdThru” to 1
when sensorless operation is selected in parameter 223.
Automatic and manual switching of feedback devices is inhibited if a loss in
parameter 320 [Exception Event1] bits 2…4 (as appropriate) is sensed on the
device to which switching was to take place. The drive will fault when it is
configured for speed feedback loss ride through and the primary device fails
when the alternate device has failed and is also configured to fault. If the alternate
device is not configured to fault, then switching to the alternate device will be
inhibited and operation on the primary feedback device will continue. Note that
operation on the primary device will continue even with that device's failure since
that fault must be configured for an alarm to allow for automatic device switch
over.
Manual Speed Feedback Device Switching
Parameter 151 [Logic Command] bit 2, “TackLoss Rst,” provides a manual
switch between active and non-active primary or alternate speed feedback devices
with a “0” to “1” bit transition. Resetting bit 2 from a “1” to a “0” causes no
change in operation. The switch is between the active feedback device (either
primary or alternate) to the non-active device. For example, if prior to the reset
the alternate device selected in Parameter 223 [Mtr Fdbk Sel Alt] is active, then
after the reset the primary feedback device selected in Parameter 222 [Mtr Fdbk
Sel Pri] will be used as the active speed feedback device. The reset activation is
prohibited if a failure is sensed in the speed feedback device to which the drive is
switching. The active device selection command is shown in parameter 152.
Manual switching between primary and alternate devices can be made while the
drive is running.
FdbkLoss
Detect
300
Logic Command
(TachLoss Rst)
Motor Spd Fdbk
to Speed
Regulator 0
1
151 2
155 12
153 16
Control Options
Speed Feedback
from Primary Device
Speed Feedback
from Alternate Device
(AutoTach Sw)
Logic Status
(Tach Loss Sw)