Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 109)

Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011 109
Detailed Drive Operation Chapter 1
• Parameter 255 [Opt0/1 RegisCtrl] configures the registration control on
port 0 and port 1 of the feedback option card.
– Set bit 0 “O0 Arm Req” or bit 16 “O1 Arm Req” to arm the registration
logic for the next trigger event. The particular latch will be armed and
ready to be strobed on the next occurrence of the trigger input.
– Set bit 1 “O0 DisarmReq” or bit 17 “O1 DisarmReq” to disarm the
registration logic for next trigger event.
• Parameter 256 [Opt0/1 RegisStat] indicates the registration control status
on port 0 and port 1 of the feedback option card.
– Bit 0 “Opt0 Armed” or bit 16 “Opt1 Armed” indicates the registration
latch is armed. The rising edge of the “Arm” request will set the “Armed”
status bit.
– Bit 1 “Opt0 Found” or bit 17 “Opt1 Found” indicates the registration
event has triggered the latch. The rising edge of the “Disarm” request
will clear the “Armed” status bit.
• Parameter 257 [Opt 0 Regis Ltch] displays the registration data of the
feedback option card at port 0. The registration data is the position
reference counter value latched by the external strobes. The strobe signal
used to trigger the latch is configurable by parameter 254 [Opt0/1
RegisCnfg].
• Parameter 258 [Opt 1 Regis Ltch] displays the registration data of the
feedback option card at port 1. The registration data is the position
reference counter value latched by the external strobes. The strobe signal
used to trigger the latch is configurable by parameter 254 [Opt0/1
RegisCnfg].
Power Loss/Ride Through The precharge function provides a current limited charging of the drive's bus
capacitor(s) and, when charging is complete, bypasses the current limiting device.
This current limited charging primarily protects the drive's input fuses and front
end rectifiers (or SCRs) from excessive inrush current. The bypass function is
needed for normal drive operation to avoid overloading the current limiting
device. In general, when precharge is active, the current limiting device is in the
circuit and when precharge is done the bypass device is active (see exceptions
below).
The ride through function can provide a motor coast, precharge and auto-restart
sequence of operation in the event of an input power dropout (power loss and
return). First the drive stops pulse width modulation (PWM) operation “coasting
the motor” and saving any remaining power stored in the drive's bus capacitor(s)
for extended control logic operating time. Next, the precharge function limits the
drive's inrush current in the event that the incoming power to the drive is
restored. Last, after the power is restored and the precharge has completed, auto-