Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control User Manual
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Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014
Chapter 3
Component Definition and Maintenance
2.
The drive will not operate properly if using single ended Quadrature
encoders. Rockwell Automation recommends using differential inputs
only for these types of encoders. Single ended outputs are only acceptable
for Positional Encoders.
20B-ENC-1 & 20B-ENC-1-MX3 Encoder Interface
This encoder interface allows the drive to be connected to a standard Quadrature
Encoder. The 20B-ENC encoder interface provides three optically isolated
differential encoder inputs for A and B phases as well as a Z track. These inputs
cannot be configured for use with a single ended Encoder. Differential encoders
only are supported. The board also provides a galvanically isolated 12V/3 W
supply to power the attached encoder. The 20B-ENC-1 Encoder interface may
be configured for 5V operation, however Rockwell recommends operation at
12V.
Figure 118 - Encoder Interface (20B-ENC-1 and 20B-ENC-1-MX3)
Operation at 5V does not allow for long cable lengths. The reason for this is that
it requires the power to be regulated within 5% at the encoder. Due to the
resistance and capacitance of the cable it would be very hard to keep the power
regulated at the encoder to 4.75V. With longer runs of cable this could drop
below the 4.75V and the encoder would not operate properly. As a general rule,
using 18Avg cabling with an Rdc of 19.3 /km the longest cable distance from
the board to the encoder is limited to 12 m (42 ft).
The 20B-ENC-1-MX3 encoder option is functionally identical to the 20B-
ENC-1 encoder with the addition of conformal coating.
shows the
recommended jumper positions for use with the PowerFlex 7000 Drive.
J3
J2
+1
2V
1
2
3
12
11
21
+5
VR
EF
1
2
3
1
2
3
12
11
21
12
11
21
Must be configured for 12V operation.
+12V
+5V
+12V
+5V
J3
Output
Config.
J2
Input
Config