Datasheet

24 Inductive Sensors
AC 2-wire OR
(parallel connection)
In principle, more than two Proximity Sensors cannot
be connected in parallel.
Provided that Proximity Sensor A does not operate
with Proximity Sensor B simultaneously and there is
no need to keep the load operating continuously, the
Proximity Sensors can be connected in parallel. In
this case, however, due to the total leakage current
of the Proximity Sensors, the load may not reset
properly.
It is not possible to keep the load operating continu-
ously with Proximity Sensors A and B in simulta-
neous operation to sense sensing objects due to the
following reason.
When Proximity Sensor A is ON, the voltage im-
posed on Proximity Sensor A will drop to approxi-
mately 10 V and the load current flows into Proximity
Sensor A, and when one of the sensing objects is
close to Proximity Sensor B, Proximity Sensor B will
not operate because the voltage imposed on Prox-
imity Sensor B is 10 V, which is too low. When Prox-
imity Sensor A is OFF, the voltage imposed on
Proximity Sensor B will reach the supply voltage and
Proximity Sensor B will be ON. Then, Proximity Sen-
sor A as well as Proximity Sensor B will be OFF for
approximately 10 ms, which resets the load for an in-
stant. To prevent the instantaneous resetting of the
load, use a relay as shown on the left.
DC 3-wire AND (serial connection) The Sensors connected together must satisfy the fol-
lowing conditions.
i
L + (N –1) x i ≤ Upper-limit of control output of each
Sensor
VS – N x VR ≥ Load operating voltage
N: No. of Sensors
V
R: Residual voltage of each Sensor
VS: Supply voltage
i: Current consumption of the Sensor
i
L: Load current
If the MY Relay, which operates at 24 VDC, is used
as a load for example, a maximum of two Proximity
Sensors can be connected to the load.
Model Connection type Method Description
Load
Load
VAC power
supply V
S
A
B
A
B
Incorrect
Correct
Load
Correct