Curtis 1238SE - Interfacing the Proportional Current Driver; Figure 17: Proportional Driver Processing

10 — VEHICLE CONTROL LANGUAGE (VCL)
pg. 109
Return to TOC Curtis 1232E/34E/36E/38E & 1232SE/34SE/36SE/38SE Manual, os 31 – May 2017
INTERFACING THE PROPORTIONAL CURRENT DRIVER
VCL code can directly interface the proportional current driver (PD), as shown in Figure 17. VCL
can change the working parameters of the PD and can provide the command.
Depending on how the PD system is to be used, certain parameters need to be set; they can be set
via the 1313/1314 programmer or via VCL.
1. PD_Enable must be set On for current control, otherwise the PD_Output will be
controlled by the VCL function Put_PWM(PWM5,xxxx), which is voltage control.
2. Hyd_Lower_Enable must be set On to use the throttle input
to control lowering in a hydraulic li/lower system.
3. Hyd_Lower_Enable must be set O to allow using a VCL
variable (VCL_PD_rottle) as the PD command.
Once the PD parameters are set, the PD_rottle variable will be mapped between PD_Min_Current
and PD_Max_Current and sent to the dither function. Note that Mapped_rottle is inverted;
lowering its value (making it more negative) increases the PD_rottle value.
e Dither function adds and subtracts from the current command to the PD based on PD_Dither_Percent,
at a rate set by PD_Dither_Period.
e dithered current command is compared to the present PD_Current and the error is fed into a PI
controller. e feedback gains are set by the parameters PD Kp (proportional gain) and PD Ki (integral
gain). e nal output is the VCL variable PD_Output, which is displayed in the 1313/1314 programmer’s
Monitor » Outputs menu as PD PWM.
e following PD processing variables are accessible by VCL:
VCL Variable
CAN Object Index
Access Decription
Mapped_Throttle
0x3211 0x00
Read Only Command from throttle section.
VCL_PD_Throttle
0x320E 0x00
Read/Write VCL-accessible PD command.
PD_Throttle
0x3210 0x00
Read Only Resultant command to the PD.
PD_Current
0x321C 0x00
Read Only Average current owing in the PD.
PD_Output
0x321E 0x00
Read Only Resultant PWM at PD output.
Quick Links (for PD text):
Figure 17 p.109
Figure 3, PD Wiring p.12
Proportional Driver
parameters p.53
Monitor
PD Input p.71
PD PWM p.72
PD Current p.72
+
+
Mapped_Throttle
PD_Throttle
-1
PD_Current
Ki
Kp
+
-
VCL_PD_Throttle
2A
0A
PD_Output
PD Enable
= On
PD PWM
PD Throttle
327670
0%
Dither Period
+ %Dither
- %Dither
Current Mapping
Dither PI Control
PD Max Current
PD Min Current
PD Dither Period
PD Dither Percent
PD Kp
PD Ki
Put_PWM(PWM5,xxxx)
Hyd
Lower
Enable = On
ShutdownPD
0%
ShutdownThrottle
or
ThrottleInvalid
or
(CANopen Interlock = On
and
CAN NMT State = Pre-operational)
0%
Italics = Other R/W Variables Bold Italics = Monitor Variables Bold = Parameters
Figure 17
Proportional driver processing.