Curtis 1239E - Page 114

10 — VEHICLE CONTROL LANGUAGE (VCL)
Curtis 1239E-1269E Manual, os 37.0 RevA – May 2021
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pg. 110
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 ramifications of
implementing changes. e motor and brake command signal chains are illustrated in Figure 18.
rottle Processing
e top section of Figure 18 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 (rottle
Type = VCL input), 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 output of the multiplying and summing 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 the rottle Menu parameters are set correctly.
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.
Aer this nal selector switch the throttle signal is the VCL variable called rottle_Command, which
is displayed as rottle Command in the 1313/1314 Monitor » Inputs menu. rottle_Command
is the nal value of the throttle signal chain that is input to the Control Mode Processing block; see
Figure 19. Checking the value of rottle Command using the 1313/1314 is a good way to see the
nal throttle signal.
If ABS (rottle_Command) > 1 count, the motor controller will output signals to the motor to
make it spin.
Quick Links:
Figure 18 p.112
rottle_Type parameter p.49
rottle menu p.49
Monitor Inputs p.77
Monitor Menu Quick Links:
Inputs » Interlock State p.77
Controller » Main State p.81
Troubleshooting
Chart p.141-148