Reference Manual

Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011 129
Detailed Drive Operation Chapter 1
Parameters 232 [Encoder0 PPR] and 242 [Encoder1 PPR] set the pulse per
revolution rating of the encoders. These parameters have a range from 10 to
20000 PPR. Parameter 156 [Start Inhibits], bit 10 “Encoder PPR” will be set if
the PPR value doesn't correspond with any of the bold values in this table:
Parameter 233 [Encdr 0/1 Config] sets the configuration options for the
encoders. The function of the bits in [Encdr 0/1 Config] are as follows:
• Bits 0…3 “Enc0 Filt bx”, or bits 16…19 “Enc1 Filt bx”, configure the
encoder input filter (see Table 15 on page 130
). 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 0…3 (or 16…19) add 100
ns filtering per stage to the encoder inputs.
• Bits 4 “Enc0 4x” and 5 “Enc0 A Phs” or 20 “Enc1 4x” and 21 “Enc1 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. Parameter 230 [Encdr0 Position] counts up for
forward rotation and down for reverse rotation. If bit 5 (or 21) 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 (or 20 and 21)
together also determine the number of edges counted per encoder pulse
(see Table 16 on page 130
). “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 (PPR)
rating per encoder revolution (for example, 4x mode increments the value
in [Encdr0 Position] by 4096 for one revolution of a 1024 PPR encoder).
• Bit 6 “Enc0 Dir” or 22 “Enc1 Dir” inverts the channel A input, thus
reversing the direction of the feedback. Note that changes in encoder
direction (bit 6 or 22) may require changing parameter 153 [Control
Options], bit 10 “Motor Dir”.
n = 2
n
= x mod 75 mod 125 mod 225 mod 375 mod 625 mod1125
01 75 125 225 375 625 1125
12 150 250 450 750 1250 2250
24 300 500 900 1500 2500 4500
38 600 1000 1800 3000 5000 9000
4 16 1200 2000 3600 6000 10000 18000
5 32 2400 4000 7200 12000 20000 --
6 64 -- -- -- -- -- --
7 128 -- -- -- -- -- --
8 256 -- -- -- -- -- --
9 512 -- -- -- -- -- --
10 1024 -- -- -- -- -- --
11 2048 -- -- -- -- -- --
12 4096 -- -- -- -- -- --
13 8192 -- -- -- -- -- --
14 16384 -- -- -- -- -- --