drive.web Manual: Control Section Control v1

Control

Section Control v1

Description	Section Control Requires *dwOption-05*, Process Control. A complete control component for a variety of closed-loop web process sections. The sum of the line speed and a negative-feedback trim term are ramped, scaled, and clamped to produce a speed demand output for the section. The trim term is scaled as a function of line speed, a second variable input, and a PI output. The PI reacts to the error between the feedback and setpoint inputs, with the sum of parallel proportional and integral process terms. The PI output clamp also clamps the integral term to avoid saturation of that term. The PI integral term's input is clamped to limit saturation from large, transient input errors.
Availability	Available only in the dw2xx & dw2xx-v2 series products Requires library: Process Control (option -05) Firmware versions 0x2024 through 0x2120
savvy-SFD Graphic
Graphic with Parameters

Parameters

PI Setpoint	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Setpoint The PI term's desired setpoint. The PI's feedback signal is subtracted from the setpoint to produce the error term.
PI Feedback	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Feedback The PI term's feedback signal. It is subtracted from the setpoint to produce the error term.
Integral Preset Value	Internal Parameter, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Integral Preset Value The integral term is immediately set to this value while Integral Preset Enable is active.
Proportional Gain	Internal Parameter, Read-write, Analog (signed 16-bit integer) 0.00 to 100.00 Section Control - Proportional Gain The input error is multiplied by this value to produce the proportional term. Larger proportional gains produce stronger responses. Too large a value can lead to system instability in the form of vibration or violent jerking. When the proportional gain is too small, system instability is characterized by slower hunting around the setpoint, possibly including large swings.
Integral Time	Internal Parameter, Read-write, Analog (signed 16-bit integer) 0.00 s to 100.00 s Section Control - Integral Time The time in which the integral term will change by 100% in response to a 100% error input. Smaller integral times produce faster responses. Too short an integral time can lead to system instability in the form of vibration or violent jerking. When the integral time is too long, system instability is characterized by slower hunting around the setpoint, possibly including large swings. 0 = Off
Integral Preset Enable	Internal Parameter, Read-write, Boolean (signed 16-bit integer) Section Control - Integral Preset Enable The integral term is immediately set to the integral preset value while this parameter is active. 0 = Inactive 1 = Preset
PI Enable	Input, Read-write, Boolean (signed 16-bit integer) Section Control - PI Enable Both the PI output, and the integral term are immediately reset to 0.00% while this parameter is inactive. 0 = Disable 1 = Enable
PI Lower Clamp	Internal Parameter, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Lower Clamp Both the PI output and the integral term can not be less than this value. When the output equals this number, the integral term is held at its current value.
PI Upper Clamp	Internal Parameter, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Upper Clamp Both the PI output and the integral term can not be greater than this value. When the output equals this number, the integral term is held at its current value.
PI Output	Internal Parameter, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Output The PI output is used to provide negative feedback in the section. The output is multiplied by the other trim scalers to produce Trim Output.
PI Error	Internal Parameter, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - PI Error Read-only. PI Feedback input is subtracted from PI Setpoint to produce the PI input error.
Proportional Term	Internal Parameter, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Proportional Term Read-only. PI Error is multiplied by Proportional Gain to produce the Proportional Term.
Integral Term	Internal Parameter, Read-only, Set to default on hard initialization, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Integral Term Read-only. PI Error is clamped and then continuously integrated according to the Integral Time to produce the Integral Term
PI Clamp Monitor	Internal Parameter, Read-only, Boolean (signed 16-bit integer) Section Control - PI Clamp Monitor Read-only. Active when the PI output is equal to the upper or lower clamp value. The Integral Term is held at its current value while the clamp is active. 0 = Inactive 1 = Clamping
Integral Error Clamp	Internal Parameter, Read-write, Analog (signed 16-bit integer) 0.00 % to 327.67 % Section Control - Integral Error Clamp Places a symmetrical clamp around the PI input error prior to passing the error to the integrator. This prevents saturation of the integral term that may be caused by large, transient input errors.
PI Integral Enable	Input, Read-write, Boolean (signed 16-bit integer) Section Control - Integral Enable The integral term is immediately reset to 0.00% while this parameter is inactive. 0 = Disable 1 = Enable
Integral Hold	Internal Parameter, Read-write, Boolean (signed 16-bit integer) Section Control - Integral Hold The integral term is held at its current value while this parameter is active. 0 = Inactive 1 = Hold
Ramped Clamp Input	Internal Parameter, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Ramped Clamp Input Read-only. The sum of the line speed and trim terms.
Upper Ramped Clamp	Internal Parameter, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Upper Ramped Clamp Ramped Clamp Output can not exceed this value. The actual, active clamp is the product of Ramp and this value.
Lower Ramped Clamp	Internal Parameter, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Lower Ramped Clamp Ramped Clamp Output can not be less than this value. The actual, active clamp is the product of Ramp and this value.
Ramp Time	Internal Parameter, Read-write, Time or Rate (signed 16-bit integer) 0.1 s to 3000.0 s Section Control - Ramp Time / Ramp Rate The actual upper and lower clamps are the product of Ramp and their preset values. Select units, either 100% ramp time in seconds, or ramp rate per second, %/s.
Ramped Clamp Enable	Input, Read-write, Boolean (signed 16-bit integer) Section Control - Ramped Clamp Enable The clamps and the Ramped Clamp Output are immediately reset to zero while this parameter is active, Reset Ramping begins at the falling edge of this input. 0 = Reset 1 = Enable
Ramp	Internal Parameter, Read-only, Set to default on hard initialization, Analog (signed 16-bit integer) 0.00 % to 100.00 % Section Control - Ramp Read-only. Increases from zero to 100% according to the ramp time / rate, following the falling edge of Ramped Clamp Enable.
Ramped Clamp Output	Internal Parameter, Read-only, Set to default on hard initialization, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Ramped Clamp Output Read-only. Equal to Ramped Clamp Input when not limited by the active clamps.
Line Speed	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Line Speed The primary speed reference for this control section.
Variable Trim	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Variable Trim Provides a trim term that is a linear function of line speed.
Fixed Trim	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Fixed Trim An independent trim term that is added with the line speed variable trim.
Trim Enable	Input, Read-write, Boolean (signed 16-bit integer) Section Control - Trim Enable The trim term is immediately reset to zero while this parameter is active, Enable. 0 = Disable 1 = Enable
Multiplier	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Multiplier The output of the ramped clamp is multiplied by this value.
Divider	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Divider The scaled output of the ramped clamp is divided by this value.
Direction	Input, Read-write, Boolean (signed 16-bit integer) Section Control - Direction Reverse the direction of the section. The polarity of the pre-clamp reference switches sign when the direction is switched. 0 = Forward 1 = Reverse
Trim Scale	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Trim Scale Scales the sum of Variable Trim and Fixed Trim to produce a final scaling factor on the PI output.
Output	Output, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Output Read-only. The function block output is the speed reference for this machine section.
Trim Output	Internal Parameter, Read-only, Analog (signed 16-bit integer) -327.67 % to 327.67 %
Upper Output Clamp	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Upper Output Clamp The function block output can not exceed this value.
Lower Output Clamp	Input, Read-write, Analog (signed 16-bit integer) -327.67 % to 327.67 % Section Control - Lower Output Clamp The function block output can not be less than this value.