Mitsubishi Electric QD70D4 User Manual page 51

3 SPECIFICATIONS AND FUNCTIONS
Logic setting*
Negative logic
(Initial value)
Positive logic
(Voltage not applied)
* : Set the logic setting using "Switch setting for intelligent function module". For details of the settings, refer to Section 5.6.
3 - 13
(1) Input signal ON/OFF status
(a) Input signal ON/OFF status
The input signal ON/OFF status is defied by the external wiring and logic
setting.
This is explained below with the example of near-point dog signal (DOG).
(The other input signals also perform the same operations as the near-point
dog signal (DOG).)
(Voltage not applied)
(Voltage applied)
(Voltage not applied)
(Voltage applied)
(b) Logic setting and internal circuit
In the QD70D, the case where the internal circuit (photocoupler) is OFF in
the negative logic setting is defined as "input signal OFF".
Reversely, the case where the internal circuit (photocoupler) is OFF in the
positive logic setting is defined as "input signal ON".
<Photocoupler ON/OFF status>
When voltage is not applied : Photocoupler OFF
When voltage is applied
External wiring
DOG
24VDC
COM
DOG
24VDC
COM
DOG
24VDC
COM
DOG
24VDC
COM
: Photocoupler ON
MELSEC-Q
ON/OFF status of near-point dog signal
(DOG) as seen from QD70D
OFF
ON
ON
OFF
3 - 13