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D-150
Programming
890CS Common Bus Supply - Frames B & D; 890CD Common Bus Drive and 890SD Standalone Drive - Frames E & F
SLEW RATE LIMIT
SETUP::MOTOR CONTROL::SLEW RATE LIMIT
Designed for all Motor Control Modes.
This function block prevents over-current and over-voltage faults occurring due to a rapidly changing setpoint.
Parameter Descriptions
ENABLE
PREF: 22.01
Default: TRUE
Range: FALSE / TRUE
When this parameter is FALSE, this function block is disabled and the setpoint is unaffected by this function block.
ACCEL LIMIT
PREF: 22.02
Default: 500.0 Hz/s
Range: 1.0 to 1200.0 Hz/s
The maximum rate at which the setpoint may accelerate away from zero.
DECEL LIMIT
PREF: 22.03
Default: 500.0 Hz/s
Range: 1.0 to 1200.0 Hz/s
The maximum rate at which the setpoint may decelerate towards zero.
Functional Description
The SLEW RATE LIMIT block obtains the setpoint from the output of the application, correctly scaled by the REFERENCE
block. The rate of change limits are applied and the setpoint is then passed on for further processing.
When the braking block determines that the internal dc link voltage is too high it issues a Hold signal. This causes the SLEW
RATE LIMIT block to hold the setpoint at its current value. This typically lasts for only 1ms, time for the excess energy to be
dumped into the dynamic braking resistor.