Parker ACR7000 Series, User Manual

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ELECTRICAL INSTALLATION
30 ACR7000 Controller Installation Guide
Encoder Functions
Each axis connector includes an encoder input.
Modes of Operation
The encoder feature has four modes of operation:
•
Quadrature
•
Step and Direction
•
CW and CCW
•
SSI (Synchronous Serial Interface)
Quadrature Mode
In Quadrature mode, two differential signals drive the onboard circuits: Encoder CHA and Encoder CHB. When
Encoder CHA leads Encoder CHB, (usually by 90 degrees) the motion is positive by convention. When Encoder
CHA lags Encoder CHB, the motion is negative by convention.
Step and Direction Mode
In Step and Direction mode, two differential signals drive the onboard circuits: STEP and DIR. A high DIR signal
and a positive edge of the STEP signal indicates a positive count, while a low DIR signal and a positive edge of the
STEP signal indicates a negative count. On the connector, Encoder CHA and STEP use the same pins and Encoder
CHB and DIR use the same pins.
CW and CCW Mode
In CW and CCW mode, two differential signals drive the onboard circuits: CW or CCW. A low CCW signal and
a positive edge of the CW signal indicates a positive count. A low CW signal and a positive edge of the CCW
signal indicates a negative count. On the connector, Encoder CHA and CW use the same pins and Encoder CHB
and CCW use the same pins.
SSI Mode
In SSI mode, one differential signal is driven out to a device, and one differential signal is received from the device:
SCLK (clock out) and SDATA (data in). The first falling edge on SCLK causes the remote device to latch its
current position value. The device then responds by synchronously shifting the data out using the SCLK rising edge
to qualify SDATA. On the connector, Encoder CHA and SCLK use the same pins, and Encoder CHB and SDATA
use the same pins. For more information on SSI mode commands, refer to ENC CLOCK, ENC DST, ENC SRC,
and ENC WIDTH in the ACR Command Language Reference (Online Help System in the Parker Motion Manager
software).
For more information on encoder modes of operation, refer to the ENC SRC command in the ACR Command
Language Reference (Online Help System in the Parker Motion Manager software).