OEM Controls SB25 - Manual (Page 2)

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Two wires connect the Digisensor to the system. The Digisensor’s Red wire connects to
the +12Vor +24V system power, and the Black wire connects to one of the SB25’s
Digisensor Inputs.
Two red diagnostic LEDS mounted on the Digisensor indicate its position (whenever
power is applied). The “Direction A” LED turns on when the potentiometer shaft is
turned counter-clockwise, and the “Direction B” LED turns on when rotated clockwise.
When the Digisensor’s shaft is centered (turned halfway between its ends of rotation)
both LEDS will be on. The section titled “Troubleshooting - Digisensor” presents
additional details.
The Digisensor Inputs on the SB25 are designed to verify the integrity of the Digisensor
signal. Digisensor signals with improper voltages, currents, or timing are rejected and
that Digisensor Input is considered to be off.
Since the Digisensor is a bi-directional sensor, one sensor can control two proportional
outputs, one for each direction.
2.1.1.1 Contactless Digisensor
An additional type of available Digisensor is the Contactless Digisensor. The Contactless
Digisensor’s output signal is identical to the standard digisensor. The Contactless
Digisensor has a non-contacting magnetic Hall Effect internal circuit for increased
rotational lifetime. The Contactless Digisensor’s signal and operation is identical to the
standard digisensor. The only connection difference is that the Contactless Digisensor
requires a third wire. The third wire is Yellow and is connected to system ground (0V)
2.1.2 Local Digital Inputs
Digital Inputs are inputs that have two states, ON or OFF. A Digital Input is driven to the
ON state by applying battery voltage. The OFF state is attained by either applying
ground (0V) or when an open circuit occurs at the digital input. Therefore, an input with
no applied voltage is OFF.
2.1.2.1 Inverted Digital Inputs
A special type of Digital Input available on the SB25 is the Inverted Digital Input. An
Inverted Digital Input is like a standard Digital Input except an Inverted Digital Input
with no applied voltage is ON.
2.1.3 Pulse Type Inputs
Pulse Type Inputs are used to count the rate of an input signal. Pulses per second are
counted and are used by the software to control an output. A pulse is measured on the
transition of the input signal from ground or open circuit to battery voltage. The SB25
can accurately monitor a Pulse Type Signal of up to 700 pulses per second.