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Encoder and position feedback, Encoder and position feedback. . . . . . . . . f-9 – Rockwell Automation 22D PowerFlex 40P User Manual, FRN 3 User Manual

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Encoder Usage and Position StepLogic Application

F-9

E223 [Find Home Freq]
This parameter sets the frequency the drive will use while it is
moving to the home position during the automatic homing routine.

E224 [Find Home Dir]
This parameter sets the direction the drive will use while it is moving
to the home position during the automatic homing routine.

To begin the automatic homing routine, activate the “Find Home” input
and then initiate a valid start command. The drive will then ramp to the
speed set in

E223

[Find Home Freq] and in the direction set in

E224

[Find Home Dir] until the digital input defined as “Home Limit” is
activated. If the drive passes this point too quickly it will then reverse
direction at 1/10th

E223

[Find Home Freq] to the point where the Home

Limit switch reactivates. Approximately one second after the routine
finds home the drive will stop. Alternately, the “Find Home Freq” and/or
“Home Limit” bits in

E248

[Enh Control Word] can be activated instead

of utilizing a digital input. The inputs or bits should be returned to
inactive after the routine is complete.

Important: After the position is reached the drive will stop. If the Find

Home is removed before the homing is complete, the drive
will begin running the position routine without the proper
home. In this case Home will not be reset and the position
will be in relation to the power up position.

Encoder and Position Feedback

Parameter

d304

[Speed Feedback] and

d305

[Speed Feedback F]

indicate the measured speed feedback or the calculated speed feedback
when no feedback device is selected. Parameter d304 [Speed Feedback]
is the number value to the left of the decimal (whole number) and d305
[Speed Feedback F] is the value to the right of the decimal (the portion
less than 1).

d306 [Encoder Speed]
Parameter

d306

[Encoder Speed] and

d307

[Encoder Speed F] indicate

the measured speed of the feedback device. This is useful if the encoder
is not used for motor speed control. However, the encoder must be used
for some purpose in order for [Encoder Speed] to indicate a value.
Parameter d306 is the number value to the left of the decimal (whole
number) and d307 is the number to the right of the decimal (the portion
less than 1).