Wesley BC-620-4CA - Manual (Page 54)

50 Curtis 1234/36/38 Manual,
OS
11
3 — PROGRAMMABLE PARAMETERS: Proportional Driver Parameters
* These parameter descriptions assume the proportional driver
is being used to drive a proportional valve, and that the PD
current control software is active (PD_Enable = On).
PROPORTIONAL DRIVER MENU
ALLOWABLE
PARAMETER RANGE DESCRIPTION
PD Enable On/Off Determines how the PWM of the proportional driver is controlled.
PD_Enable On/Off When programmed On, it is controlled by the controller’s PD current control
OptionBits1 [Bit 6] software. When programmed Off, it is controlled by the VCL function
Put_PWM (PWM5, value); see Figure 16, page 97.
Hyd Lower Enable On/Off When programmed On, lowering is controlled by throttle position.
Hyd_Lower_Enable On/Off When programmed Off, lowering is controlled by the VCL variable VCL_PD_
OptionBits1 [Bit 7] Throttle; see Figure 16, page 97.
PD Max Current 0.0–2.0 A * The Lower speed is determined by the aperture of the proportional valve.
PD_Max_Current 0–607 This parameter sets the maximum allowed current through the valve,
which in turn defines its aperture.
PD Min Current 0.0–2.0 A * Sets the minimum allowed current through the proportional valve.
PD_Min_Current 0–607 Most proportional valves need a non-zero closed current in order to start
opening immediately when Lower is requested.
PD Dither % 0–100 % * Dither provides a constantly changing current in the coil to produce a rapid
PD_Dither_Percent 0–32767 back-and-forth motion of the valve; this keeps the valve lubricated and allows
low-friction, precise movement. The PD Dither % parameter specifies the
amount of dither as a percentage of the PD max current, and is applied in
a continuous cycle of add%-subtract%.
PD Dither Period 16–112 msec * Sets the period for proportional valve dither.
PD_Dither_Period 1–7
PD Kp 1–100 % * Sets the proportional gain of the current feedback controller. Higher gains
PD_Kp 82–8192 force the control loop to respond quickly but may cause oscillations.
PD Ki 1–100 % * Sets the integral gain of the current feedback controller. Integral gain tries
PD_Ki 327–32767 to force the error to zero. Higher gains force the control loop to respond
quickly but may cause oscillations.