Precautions With Connecting Two-Wire Dc Sensors; A-3-1 Relation Between On Voltage Of A Unit With Dc Inputs And Sensor Residual Voltage; A-3-2 Relation Between On Current Of A Unit With Dc Inputs And Sensor Control Output; Current - Omron GX-ID1611 User Manual

A Appendix
A-3 Precautions with Connecting
Two-wire DC Sensors
When using a two-wire DC sensor with a DC input type Slave Unit, check that the following conditions
have been met. Failure to meet these conditions may result in operating errors.
A-3-1 Relation between ON Voltage of a Unit with DC Inputs and Sensor
Residual Voltage
≤ V
V - V
ON CC R
V : I/O power supply voltage (The allowable power supply voltage range is 20.4 to 26.4 V, so 20.4 V will be
CC
used here to allow for the worst possible conditions.)
V : ON voltage for a Unit with DC inputs
ON
V : Sensor's output residual voltage
R
It is sometimes possible to satisfy the above equation by adjusting the I/O power supply voltage (V
to 26.4 V.
A-3-2 Relation between ON Current of a Unit with DC Inputs and Sensor
Control Output
(min) ≤ I
I
OUT ON
I : Sensor control output (load current)
OUT
I : ON current of a Unit with DC inputs
ON
I is calculated as follows:
ON
I = (V
ON CC
V : Internal residual voltage of a Unit with DC inputs
F
R : Input impedance of a Unit with DC inputs
IN
When I is smaller than I
ON
The bleeder resistor constant can be calculated using the following equation.
R ≤ (V
- V ) / (I
CC R
Power W ≥ (V
CC
2-wire
V
sensor
A - 76
≤ I
(max)
OUT
- V - V ) / R
R F IN
(min), connect a bleeder resistor R.
OUT
(min) - I )
OUT ON
2
− V / R × 4 [allowable margin]
)
R
DC input
R
R
R IN
type slave
V
CC
GX-series EtherCAT Slave Unit User's Manual
)
CC