Curtis 1238SE - Page 108

10 — VEHICLE CONTROL LANGUAGE (VCL)
Curtis 1232E/34E/36E/38E & 1232SE/34SE/36SE/38SE Manual, os 31 – May 2017 Return to TOC
pg. 104
e throttle and brake signal chains within the controller are sophisticated and exible. Before applying
VCL to modify these chains, it is important to fully understand the ramications of implementing
changes. e motor and brake command signal chains are illustrated in Figure 15 and discussed below.
rottle Processing
e top section of Figure 15 shows the throttle processing. e throttle signal chain ows le to right
starting with the throttle pot (wiper). e voltage on the throttle wiper input (pin 16) is processed by
the controller and has the VCL variable name rottle_Pot_Raw. is variable is displayed as rottle
Pot (voltage) in the Monitor » Inputs menu of the 1313/1314 programmer. is throttle signal is then
modied by the rottle Type Processing and rottle Mapping blocks.
The Throttle Type Processing block combines the Throttle_Type parameter and the throttle
potentiometer input (rottle_Pot_Raw) to create a 16-bit variable containing the magnitude of the raw
command. is raw command passes to the rottle Mapping block, which re-shapes the throttle signal
magnitude and direction based on the various rottle Menu parameters and the direction inputs.
Following the rottle Mapping block are two switches whose purpose is to give the throttle signal a
small value (1 for the forward switch, and –1 for the reverse switch) to indicate that a direction switch
is On—but only if the throttle signal output from the rottle Mapping block = 0.
e signal then passes through a selector switch. If the rottle_Type parameter is set to 5 the
rottle Mapping block output signal is ignored and the command comes from the VCL variable
VCL_rottle. e VCL program manipulates the VCL_rottle variable to get a throttle command.
When the rottle Type is set to 1–4, the variable VCL_rottle does nothing, and the rottle
Mapping block output signal passes through.
Aer the “rottle Type = 5” switch, the throttle signal is modied by the multiplying and summing
nodes. ese nodes can be adjusted by VCL through the variables rottle_Multiplier and rottle_
Oset. is is the basic input point for creating functions like MultiMode, dual drive algorithms, and
height vs. speed control. Note that the throttle multiplier has a built-in “divide by 128.” is allows
the VCL to either multiply (rottle_Multiplier > 128) or divide (rottle_Multiplier <128) the
nominal throttle value. Typically the default multiplier is set to 128, thus having no net eect. Both
rottle_Multiplier and rottle_Oset can be positive or negative.
e throttle signal next passes through a limiter that is active only if a pump motor is being operated (Pump
Enable = On, and optionally if Regen Lower Enable = On, the pump motor can operate in reverse). is
limiter acts to constrain the pump’s throttle signal to 100% (positive for forward motion, or negative when
Regen_Lower_Enable is On), which is appropriate for controlling a hydraulic pump motor in speed mode.
e output of the multiplying, summing and (pump) limiter nodes is the VCL variable called Mapped_
rottle, which is displayed as Mapped rottle (percent) in the Monitor » Inputs menu of the 1313
handheld or 1314 PC programmers. A VCL program can control this throttle signal by changing the three
variables VCL_rottle (only if rottle Type = 5), rottle_Multiplier, and rottle_Oset. e eect
of these variables can be observed as in the 1313/1314’s Mapped rottle or the VCL Mapped_rottle
variables. Checking the value of Mapped rottle (Mapped_rottle) is a good way to see if your rottle
Menu parameters are set correctly.
Prior to passing to the nal selector switch, the throttle signal passes through a selector which
validates for forward pump operation in speed modes. It will set the pump throttle signal = 0% when,
in either speed mode, Pump Enable = On and the Mapped_rottle is < 0 (negative). is will prevent
a pump operating in reverse when Regen Lower Enable = O, or if the controller is in Torque Mode.
e throttle signal continues to a selector switch that will set the throttle signal = 0% if any of the
following conditions are present: Interlock_State = O, a fault has set throttle request = 0% (Fault
action = Shutdownrottle), or if Main_State ≠ 5 or 10, or an invalid throttle. An invalid throttle is
when both the Forward and Reverse switches are On, for example.
Quick Links:
Figure 15 p.105
rottle_Type parameter p.46
rottle menu p.46
Pump parameter menu
Speed Mode = 0 p.31
Speed Mode = 1 p.32–39
Monitor Inputs p.70
Monitor menu
Inputs » Interlock State p.70
Controller » Main State p.74
Troubleshooting
Chart p.132–139