5 Installation and Wiring
5 - 70
NX-series NX1P2 CPU Unit Hardware User’s Manual (W578)
This section explains the wiring of an NX1W-ADB21/-DAB21V/-MAB221 Analog I/O Option Board.
An Analog I/O Option Board provides analog input and analog output. For all models, the same method
is used to connect analog input and analog output.
Refer to 3-4 Analog I/O Option Board on page 3-25 for the terminal arrangement for each model of the
Analog I/O Option Board.
Analog Input
5-4-12 Wiring the Analog I/O Option Board
When you connect a computer or other peripheral device to a Controller that has a non-isolated
DC power supply, either ground the 0-V side of the external power supply or do not ground it at
all.
If the peripheral devices are grounded incorrectly, the external power supply may be short-cir-
cuited. Never ground the 24-V side of the power supply, as shown in the following figure.
Internal Circuits
Internal
power supply
circuit
(Non-isolated)
CPU Unit
Cable
External device
(e.g. computer)
External power supply (Unit power supply)
Non-isolated Option Board,
Communication Interface Unit, etc.
Unit power
supply terminals
Non-isolated DC
power supply
Analog input 2
Analog ground
I I 1
V I 1
COM()
I I 2
V I 2
56 k
250
250
180 k
180 k
Internal circuits
Analog input 1
. . .
. . .
56 k