Service manual

Electrical Service Manual V4.0
6
6-3
CENTRAL COMMAND II
ON-OFF (CENTER OFF)
For the controller to switch a connected component on and off it must receive an input
signal from one of the switches on the machine. The controller knows to turn components
on and off based on the signal it receives from that switch . These switches are part of a
tri-state logic system that the controller uses to interpret the input from the switches. The
switches for the inputs are fed a reference voltage that is created by the controller. This
reference voltage is either, Low, ( 0.1 volt +/- 0.1 volt), or High, (4.9 volts +/- 0.1 volt). The
input circuits on the controller have an unaffected (nothing connected) state of 0.8 to 2.5
volts +/- 0.2 volts (Mid). When you turn a switch for a component on, a switched reference
voltage is applied to the input circuit causing the input voltage to either go High (4.9 Volts
+/- 0.1 volt) or Low (0.1 volt +/- 0.1 volt).
VARIED VOLTAGE
For circuits that require a varied output such as the throttle and solution output, we use a
varied voltage input. The way these inputs work is a Low (0.1 volt +/- 0.1 volt) reference
voltage is sent to one side of the coil on a 5K potentiometer and a High, (4.9 volts +/- 0.1
volt), reference voltage is sent to the other side of the coil on the same 5K potentiometer.
The potentiometer sums the voltage together and the outputs a varied voltage signal from
(Low), 0.1 volt +/- 0.1 volt to, (High) 4.9 volts +/- 0.1 volt. on the center pin, (wiper), of the
potentiometer. This voltage is then fed to the input of the controller. When the controller
receives the varied voltage signal from the potentiometer it controls the relative output ac-
cordingly.
IMPORTANT NOTE: The throttle signal on our machines is the only input on our control
system with an unaffected (Low) input voltage of 0.1 +/- 0.1 volt.
OUTPUTS
The outputs on the Central Command II system that are controlled by the controller operate
quite different than previous control systems. They no longer have a circuit breaker or a
direct mechanical link to a switch on the machine. The outputs are turned on by the con-
troller, based on numerous inputs and internal calculations. These outputs are pulse-width
modulated outputs which allows us to soft start our components, control their operating
speeds, dynamically control down-pressure and turn components on and off based on other
functions of the machine.
IMPORTANT NOTE: When measuring outputs you must have within 1 volt of battery volt-
age to consider the output on.