125 pi control – Rockwell Automation Liqui-Flo DBT Reach Drive User Manual
Page 56
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DBT Reach Drive User Manual
Bit 1 - Invert Error
•
Enables/disables the option to invert the sign of the PI error signal. Enabling this
feature creates a decrease in output for an increasing error and an increase in
output for a decreasing error.
Bit 2 - Preload Mode
•
Enabled = Initializes the PI integrator to the commanded speed while the PI is
disabled.
•
Disabled = The PI integrator is loaded with the PI Pre-load (133) while the PI is
disabled.
Bit 3 - Ramp Ref
•
Enables/disables ramping the reference used from PI Feedback to the selected PI
Reference after PI is enabled. The active accel time is used for the PI ramp
reference slew rate. The ramping is bypassed when the reference equals the
setpoint.
Bit 4 - Zero Clamp
•
Enables/disables option to limit operation so that the output frequency always has
the same sign as the master speed reference. This limits the possible drive action to
one direction only. Output from the drive will be from zero to maximum frequency
forward or zero to maximum frequency reverse.
Bit 5 - Feedback Sqrt (Square Root Feedback)
•
Enables/disables the option of using the square root of the feedback signal as the PI
feedback. This is used for pressure control because fans and pumps vary pressure
with the square of the speed.
Bit 6 - Stop Mode
•
Enabled = A Stop command is issued to the drive and the PI Loop will continue to
operate during the decel ramp.
Bit 7 - Anti-Windup
Enabled = The PI Loop will automatically prevent the integrator from creating an
excessive error that could cause instability. The integrator will be controlled without the
need for PI Reset or PI Hold Inputs.
Bit 8 - Torque Trim
•
PI Output summed into the Torque Input.
Bit 9 - % of Ref
•
PI scaled to % of Ref instead of Max Frequency.
Controls the PI regulator. Note that you must use a datalink to write to this parameter
interactively from a network.
125
PI Control
Range:
See figure 3.6
Default:
See figure 3.6
Access:
2
Path: Speed Command>Process PI
See also:
124-138