Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 150)

150 Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014
Chapter 3 Component Definition and Maintenance
Quadrature Encoder Operation
The Universal Encoder Interface will accept either single or dual quadrature
encoders. Configuration of the board to accept the encoders is done through
jumpers on J4.
Boards shipped from the factory come defaulted to single quadrature encoder
configuration (Consult factory for availability of dual Quadrature Encoder
options).
For dual encoder configurations, the primary encoder is wired to pins 1 through
7 on the 1492-IFM20 module.
To select the dual encoder option, remove the CD_QUAD jumper and place it in
PARK. This will configure the board to accept two individual quadrature
encoders. In this mode, the drive can switch between encoders for applications
such as Synchronous Transfer between two motors with each having their own
encoder.
For redundant encoder option, remove both the CD_QUAD and
POL_QRDNT jumpers and place them in PARK. With this configuration, the
drive will switch over to the redundant encoder when it detects a problem with
the primary encoder.
Positional Encoder Operations
(1)
Besides quadrature encoders, the Universal Encoder Interface will also accept
positional (absolute) encoders. Parallel positional data is converted to a serial
stream and transmitted to the DPM when requested by the drive. The board will
also generate “pseudo” quadrature differential signals, including a zero position
mark, derived from the binary data to the DPM.
There are three different positional encoder configurations available. For all of
these configurations remove the ENC_TYPE jumper. The other jumpers
configure the board for the type of positional data (Gray Code or Natural
Binary) set by CD_DQUAD and High or Low True data set by POL_QRDNT.
1. Gray code, Low True . In this configuration the board will invert the
incoming gray code data and then convert it to binary for transmission to
the DPM.
2. Natural Binary, Low True . No conversion is done on the incoming data
but it is inverted.
ATTENTION: When the drive switches over to the redundant encoder, it cannot
switch back without recycling control power.
(1) Consult factory for availability of Positional Encoders.