Wesley BC-620-4CA - Manual (Page 93)

Curtis 1234/36/38 Manual,
OS
11 89
2 3 J U LY 2 0 0 8 D R A F T
Set_DigOut(DigOut6)
will set Digital Output 6 On (active). VCL can monitor the present value of
a digital output driver: the bit variable Digx_Output (where “x” is the digital
output channel number) is automatically filled with the present value of the
driver output (On or Off).
It is important to note that all outputs are active Low. With 100% PWM
or an output of “On,” the FET or transistor will be pulling hard to ground. A
DVM on the output will measure near 0 volts.
Potentiometer Inputs
These controllers have two potentiometer inputs, which are typically used for
throttle and brake. Many features (mapping, acceleration rates, etc.) are built
in as 1311 parameters. Still, there are times that these potentiometer inputs
may be needed for other functions such as steering angle or height sensing,
or simply as data inputs. The standard way to input pot information is to set
the 1311 parameter Throttle Type (or Brake Type) to an appropriate value of
1–4 as shown on pages 13–16. When set to a value of 1–4, the resulting signal
chain can operate without the use of any VCL.
However, if an OEM wishes to control the throttle (or brake) signal chain
in VCL or use the throttle (or brake) inputs for signals that are not throttle (or
brake) signals, then the 1311 parameter Throttle Type (or Brake Type) should
be set to a value of 5 (page 17). Setting the 1311 parameter Throttle Type (or
Brake Type) to a value of 5 changes the routing of the appropriate signal chain
(either throttle or brake) and allows the VCL programmer access to the Throttle
Pot (or Brake Pot) output variables; see Figure 14 (page 92).
When the Throttle Type setting = 5, the Throttle_Pot_Output is a VCL
variable that the OS will update with the current value of the throttle pot input.
Similarly, when the Brake Type setting = 5, the Brake_Pot_Output is a VCL
variable that the OS will update with the current value of the brake pot input.
However, the value of the Throttle_Pot_Output (or Brake_Pot_Output) will
remain clamped to zero until the VCL function Setup_Pot() is executed.
Typically the Setup_Pot() function is executed at the beginning of a VCL
program to define the potentiometer input connection as THREE_WIRE (uses Pot
High and Pot Low connections), TWO_WIRE (variable resistor, or rheostat, uses
Pot Low but no connection to Pot High), or ONE_WIRE (a voltage input, no
connection to either Pot High or Pot Low). THREE_WIRE potentiometer con-
nections are the same as the 3-wire potentiometer connections shown on page 15
for a Throttle Type 2.
TWO_WIRE potentiometer connections are the same as
the 2-wire potentiometer connections shown on page 14 for a Throttle Type 1.
ONE_WIRE potentiometer connections are the same as the Voltage Source or
Current Source connections shown on page 15 for a Throttle Type 2.
Note that the Setup_Pot() function will only work (and is only needed)
if the corresponding Type is set to 5 (Throttle Type = 5 or Brake Type = 5).
Setup_Pot(THROTTLE_POT,THREE_WIRE)
will set up the throttle pot input for wiring using all three connections (pins
15, 16, 18).
7 — VCL