Flowserve 400MD Logix - Manual (Page 38)

FINAL_VALUE_CUTOFF_LO: If FINAL_VALUE is less than FINAL_VALUE_CUTOFF_LO the positioner will saturate the actuator in a closed posi-
tion. There is a 1 percent hysteresis added, so FINAL_VALUE must be more than 1 percent of FINAL_VALUE_CUTOFF_LO, before the posi-
tioner will allow the valve to start opening. This feature is disabled in SOFTSTOP_LOW is less than or equal to 0 percent.
FINAL_POSITION_VALUE: This is the valve’s stem position, as sensed by the positioner. This value is always reported in percent of stroke.
TEST_MODE: This parameter is used to enable the diagnostic parameters in the Transducer Tech Block for continuous update. Also, this can be used to
set the mode to allow write to the DAC directly to test the spool control.
CONTROL_CONFIG: These are flags used to set the configuration of the positioner.
• Local Panel disable allows the user to disable any button pushes or changes to be made at the device.
• Continuous Friction Mode Enable allows the user to enable or disable the continuous friction mode.
• Pressure Control Enabled allows the user to enable or disable the pressure control function.
• Pressure Sensor Board Present is set by the device indicating that a functioning pressure board has been installed into the device.
• Single Action Enabled allows the user to select between single acting and double acting.
PGAIN: The Logix 3400MD digital positioner uses a special gain algorithm. The proportional gain increases with a decrease in error. This allows for maxi-
mum resolution and speed. GAIN_UPPER is the upper limit to proportional gain.
DGAIN: The Logix 3400MD digital positioner uses a special gain algorithm. The proportional gain increases with a decrease in error. This allows for maxi-
mum resolution and speed. GAIN_ LOWER is the lower limit to proportional gain.
IGAIN: In addition to proportional gain the Logix uses integral as well. This in the integral gain setting. Typically this is set to 10.
CALIBRATE: This parameter initiates calibration. Two types of calibration are available Stroke, Pressure Sensors (advanced/pro models only).
To learn more about calibration refer to the Calibration section of this document.
STOP_HIGH_POS: Software imposed stroke limit. The positioner will not allow the valve to open beyond the value shown in this parameter.
STOP_LOW_POS: Software imposed stroke limit. The positioner will not allow the valve to close beyond the value shown in this parameter, normally psi.
CYCLE_CNTR This parameter counts the number of cycles that have occurred.
CYCLE_DEADBAND In order for a cycle to be counted it must be greater than the value in this field.
CYCLE_CNTR_LIM_CNTR If CYCLE_COUNTER exceeds this value, the LED lights will start to blink Green, Red, Green, Green and a warning will
be generated in TRAVEL_FLAGS.
TRAVEL_ACCUM: Total distance the valve stem has traveled.
TRAVEL_ACCUM_DEADBAND: Amount in percent of stroke the valve must move in order for the movement to be added to TRAVEL_ENG.
TRAVEL_ALERT:_LIM If TRAVEL_ENG exceeds this value, the LED lights will start to blink Green, Red, Green, Green and a warning will be gener-
ated in TRAVEL_FLAGS.
STROKE_LENGTH: Stoke length of valve. This value is used to calculate TRAVEL_ENG.
TRAVEL_UNITS Units of measure used to calculate TRAVEL_ENG.
PRESS_UNITS Units of measure that pressure sensor readings are expressed in.
TEMP_UNITS Units of measure that temperature is expressed in.
Note: The stroke limiting feature could be used to make a valve very responsive to small steps. By increasing the nominal gain values, and
limiting the stroke speed, small steps would be subject to very high gains. When active, the algorithm scales back large step sizes, thus limiting
the undesired effects large gains normally demonstrate on large step sizes, such as overshoot.
Logix 3400MD Digital Positioner LGENIM3405-02 11/13
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