About Grounding - Panasonic MICRO-IMAGECHECKER A200 Series Hardware Manual

Input/Output Terminals (Input/Output Ports)
3.7

About Grounding

3.7

About Grounding

Attaching a Ground to Prevent Effects of Noise
− The controller can tolerate the noise present in a normal environment. Provide a
ground when installing it in a particularly noisy environment.
Use a Dedicated Ground Wire
− Use a third−type ground of 0.3 to 1.25mm
100Ω or less.
− Locate the ground as close as possible to the controller and minimize the length of
the ground wire.
− Use a dedicated ground wire in order to avoid negative effects from ground wires
shared with other devices.
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Note on connecting the positive terminal of the power supply to ground
− Install another power supply for A−series controller. Do not connect the positive
terminal of the power supply to ground (see
− Should the positive terminal of the power supply be connected to ground, do not
connect the FG terminal of an external device such as PLC, etc. because the SG
terminal of the A−series may be connected to ground via the FG terminal (see
the drawing below).
The SG terminal of the A−series is internally connected to the GND (0V) terminal.
For some computers, the SG terminal of RS232C port and the outer shell of the
connector have already been connected. In this case, the SG terminal of the
A−series and the FG terminal of an external device such as PLC, etc. will be
connected. If the positive terminal of the power supply to ground, a short−circuit
condition occurs, resulting in damaging the internal circuit.
3 − 12
Inverter and
other devices
2
or more and with ground resistance of
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in the drawing below).
1
A200/A100 Hardware
Inverter and
other devices
in
2