Can Bus And Rs-485 Termination Resistor; Module Power Supply Wiring; Analog Sensor Power Supply Wiring; Digital Inputs (Di) - Generac Power Systems Power Zone Pro Owner's Manual

Installation and Operation
resistors. The Main Controller end is already terminated.
See CAN Bus and RS-485 Termination

CAN Bus and RS-485 Termination Resistor

For CAN and RS-485, both ends of the pair of signal
wires (High and Low) must be terminated. The
termination resistors on a cable should match the
nominal impedance of the cable, 120 Ohm differential. If
there are multiple devices along the cable, only the
devices on the ends of the cable need termination
resistors. Figure 3-2 shows an example of how to
terminate a network. The Generator Main Controller
already contains a termination resistor. Once the other
end of the cable is determined, the termination can be
placed at that end. If the Governor module is the furthest
one on the bus, the termination can be placed close to
the Governor on its bus wires.
NOTE: The wires depicted in
A
A
B
A CAN or RS-485 Device
B 120 Ohm Termination Resistor
C High
D Low
Figure 3-2. CAN Bus or RS-485 Bus Network Termination

Module Power Supply Wiring

Each module in the system requires at least one power
supply. Some modules with high current requirements
such as an ignition module or governor module will also
have a separate high current supply wired to the battery.
Some modules may only have the high current supply
direct to the battery. The Main Controller has the
provision to connect four modules directly to its pins. If
there are more modules that need to be connected, the
power supply pins can be brought out to a common
terminal block. #16 gauge wires are recommended for
these connections.
12
Resistor.
Figure 3-2 are twisted pair.
A
A
C
D
B
006355

Analog Sensor Power Supply Wiring

The Main Controller provides precision voltage supplies
for these types of sensors (either 5 V or 12 V), so they
can be wired as appropriate per the sensor data sheet.
Some sensors do not require a precise voltage supply
and can use battery supply directly if appropriate. The
precision voltage supplies from the Main Controller are
current limited in case of shorting and are capable of
supplying a maximum of 1 A per supply. The total current
draw of all sensors powered from the 12 V precision
supply is limited to a maximum of 1 A. The same is true
for the precision 5 V supply. #18 gauge wires are
recommended for these connections.

Digital Inputs (DI)

The Main Controller provides the facility to connect to
multiple digital inputs. Each digital input is normally a
closure to ground (such as a switch). The inputs are
pulled up to 5 V on the controller board. Voltages can be
applied to the Digital Input provided the voltages obey the
limits in Specifications. There are specially designated
digital inputs for connections that switch at high speeds
(>100 Hz such as a PWM input). #18 gauge wires are
recommended for these connections.

Digital Outputs (DO)

The Main Controller provides multiple digital outputs.
Each digital output is an electronic switch closure to
ground. The voltage at each output is determined by
what voltage the load is connected to. This voltage shall
not exceed 35 V . There are specially designated
digital outputs for connections that switch at high speeds
(>100Hz such as PWM outputs). #18 gauge wires are
recommended for these connections.

High Current Digital Output

This output is intended to be for air/fuel ratio control. It is
a special high current output for driving solenoid valves.
#18 gauge wires are recommended for this connection.

General Purpose Analog Inputs (GPAI)

Typically analog sensors can have different types of
output: Current Loop 4-20 mA, Voltage (0-5 V or 0-10 V
or scalable), or Resistive type. Any of these types of
sensors can be wired to the 12 GPAI inputs on the Main
Controller. Configuration settings are used to adapt the
input to the sensor attached. The GPAI inputs are
multiplexed and read relatively slowly. If a faster
response is required, use one of the two Special Analog
Inputs covered in Special Analog
Usually a sensor is either two or three wire. Two wire
sensors present a resistance to the Main Controller and
are wired between ground and the analog input pin.
Owner's Manual for Power Zone Pro Main Controller
Inputs.