Model
Connection type
Method
Description
AC 2-wire OR
In principle, more than two Proximity Sensors cannot
be connected in parallel.
Incorrect
(parallel connection)
Load
Load
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.
A
B
B
Correct
It is not possible to keep the load operating
continuously with Proximity Sensors A and B in
simultaneous operation to sense sensing objects
due to the following reason.
A
VAC power
supply VS
When Proximity Sensor A is ON, the voltage
imposed on Proximity Sensor A will drop to
approximately 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 Proximity Sensor B is 10 V, which is too
low. When Proximity 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 Sensor A as well as Proximity Sensor B
will be OFF for approximately 10 ms, which resets
the load for an instant. 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
following conditions.
Correct
iL + (N –1) x i ≤ Upper-limit of control output of each
Sensor
Load
VS – N x VR ≥ Load operating voltage
N: No. of Sensors
VR: Residual voltage of each Sensor
VS: Supply voltage
i: Current consumption of the Sensor
iL: 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.
38
E2E/E2E2 Cylindrical Proximity Sensor
OMRON [ OMRON ELECTRONICS LLC ]
