Manual 26166V1 MicroNet Simplex & MicroNet Plus
Woodward 33
Power Supply Slots (PS1, PS2)
A smaller 2-slot wide power supply has been designed for the MicroNet Plus chassis, thus allowing (2)
more slots for I/O. Each power supply is located under different fan sets for improved reliability. The
redundant smart fans are located above and below each power-supply for improved airflow. Each power
supply provides input failure (AC_FAIL) and output failure (PWR_ALM) fault information to the CPU slots.
Power supplies are located under different fan sets to improve reliability, airflow, and temperature
performance.
Three different 2-slot wide power supplies are available for use: a low voltage (24 Vdc input), a high
voltage (120 Vac/dc input), and a high voltage 220 Vac input version. Refer to the power-supply
section for additional information.
Redundant Smart Fans
Each smart-fan provides a tachometer output to the CPU slots. The CPU monitors the fans for slow
operation or fan-failure. A GAP application fault is provided for each fan. Quick-connect FAN connectors
are utilized for improved field replacement. (Do not replace fans without taking proper ESD precautions.)
The motherboard provides individual, short-circuit protected, +24 V Fan power to each fan.
Motherboard Terminal Block (TB1)
The MicroNet Plus chassis includes a terminal block that provides CPU1 and CPU2 Remote reset inputs.
The same terminal block provides access to +24 Vdc motherboard power (3 terminals) through two
separate 5 A fuses. If a direct short of this power output occurs, the fuses will blow to protect the
motherboard, and the power supplies will shut down with a 24 Vdc power fault. Replacement fuses can
be ordered as Woodward P/N 1641-1004. The system must be shut down to replace the fuses safely.
24 Vdc Motherboard Power
Redundant systems—Not recommended for use.
Simplex systems—This power may be used for local Ethernet switch power upon successful EMC
testing. Consider carefully the possibility of shorts and the type of connector wiring used.
The Motherboard +24 Vdc power outputs should be used locally in the
same MicroNet cabinet only in rare instances, as the quality of this
supply is critical to proper system operation.
CPU Remote Reset Inputs (RST1, RST2)
Each CPU may be reset by either using the front-panel reset button or a remote-reset input provided on
the motherboard. The remote-reset inputs are available at the TB1 terminal block located at the bottom
center of the chassis. The individual remote resets for each CPU are designated RST1+, RST1– for slot
A1 and RST2+, RST2– for slot A8. These inputs are optically isolated on each respective CPU module
and require both a 24 V(+) and a common(-) to be wired. A momentary high will cause a CPU-reset.
Chassis Overtemp Alarm
The MicroNet Plus 8-slot chassis provides (2) over-temperature switches on the motherboard. The over-
temperature switches will trip at 65C 3C and communicate this warning to the CPU and GAP
application.
Chassis Outline Drawing
The MicroNet Plus 8-slot chassis is physically the same dimensions as the current MicroNet Simplex 6-
slot chassis.
Notes:
Add ~2” (~5 cm) to the depth dimension to account for the cable saddles that are not shown on the
outline drawing below.
The PE ground connection point is located underneath the left side of the chassis.
To ensure compliance with the EMC certification, all chassis mounting screws (#8-32 M4) should be
installed to properly ground the chassis to the mounting plate.
For proper airflow, the installation should allow a 3” (8 cm) air gap above and below the chassis.
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