Mitsubishi Electric Melsec Q Series User Manual page 66

4 SETUP AND PROCEDURES BEFORE OPERATION
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(2) Q68ADV
GND
1 Shielded
1 Use a twisted two core shielded wire for the power wire.
2 Shows input resistance of the Q68ADV.
3 "A.G." terminal does not normally require wiring. However, it can be used as
GND for external device ground under the following conditions.
(1) When there is a difference in polarity between "A.G" and "GND for external
device".
(2) As an alternative for 0 V input when only the + side is open on a ± wire.
4 Always use a ground. In addition, ground the FG of the power supply module.
POINT
In an unused channel, if terminals remain open, an erratic digital value may be
output.
To prevent this, take any of the following measures.
1. Select Disable in A/D conversion enable/disable setting for the unused channel.
Note that changing the setting from Enable to Disable will reduce the
sampling time.
2. Short-circuit the input terminals (terminal V+ and V-) of the unused channel.
3. Connect the A.G. terminal to the GND terminal of the external device.
(3) Q68ADI
GND
1 Shielded
1 Use a twisted two core shielded wire for the power wire.
2 Shows input resistance of the Q68ADI.
3 "A.G." terminal does not normally require wiring. However, it can be used as
GND for external device ground under the following conditions.
(1) When there is a difference in polarity between "A.G" and "GND for external
device".
4 Always use a ground. In addition, ground the FG of the power supply module.
2
V+
V-
A.G.
FG
3
4
I+
250
I-
A.G.
FG
3
4
MELSEC-Q
500k
500k
500k
2
500k
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