Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual User Manual
Page 139
Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013
139
Detail Drive Configuration and Operation
Chapter 1
[Encdrx Config] sets the configuration option for the encoder. The bits for
[Encder x Config] are broken down as follows:
•
Bit 0 - “Enc Filt bt0”
•
Bit 1 - “Enc Filt bt1”
•
Bit 2 - “Enc Filt bt2”
•
Bit 3 - “Enc Filt bt3”
•
Bit 4 - “Endr 4x”
•
Bit 5 - “Encdr A Phs”
•
Bit 6 - “Encdr Dir”
•
Bit 7 - “Reserved” (not used)
•
Bit 8 - “Reserved” (not used)
•
Bit 9 - “Edge Time”
•
Bit 10 - “Reserved” (not used)
•
Bit 11 - “Reserved” (not used)
•
Bit 12 - “SmplRate bt0”
•
Bit 13 - “SmplRate bt1”
•
Bit 14 - “SmplRate bt2”
•
Bit 15 - “SmplRate bt3”
•
Bits 16…31 - “Reserved” (not used)
The function of the bits in [Encdrx Config] is explained here.
•
Bits 0 “Enc Filt bt0”, 1 “Enc Filt bt1”, 2 “Enc Filt bt2”, and 3 “Enc Filt bt3”
configure encoder input filter (see
Table 7
on page
140
). The filter requires
the input signal to be stable for the specified time period. Input transitions
within the filter time setting will be ignored.
•
Bits 4 “Encdr 4x” and 5 “Encdr A Phs” determine how the encoder
channel A and B signals will be interpreted. Typically, both encoder phases
A and B are used so that direction information is available. The parameter
230 [Encdr0 Position] counts up for forward rotation and down for
reverse rotation. If bit 5 is set, then the B phase signal is ignored. As a
result, the encoder position will only increase, regardless of rotation
direction. Bits 4 and 5 together also determine the number of edges
counted per encoder pulse (see
Table 8
on page
140
). “4x” sampling counts
both rise and fall of both A and B encoder phases, hence 4 edges per pulse.
In 4x mode, the encoder position will change by four times the encoder
pulses per revolution rating (PPR) per encoder revolution (for example, it
increments the value in parameter 230 [Encdr0 Position] by 4096 for one
revolution of a 1024 PPR encoder).
•
Bit 6 “Encdr Dir” inverts the channel A input, thus reversing the direction
of the feedback.