Rockwell Automation Allen-Bradley 1769-IQ16 - Page 50

50 Rockwell Automation Publication 1769-IN088A-EN-P - February 2011
Chapter 2 Module Wiring
The minimum resistor (R) value depends on the current sinking capability of the encoder.
External resistors are required if they are not internal to the encoder. The pull-up resistor (R) value
depends on the power supply value. To calculate the maximum resistor value, use this formula:
where:
· R = maximum pull-up resistor value
· Vdc = power supply voltage
· Vmin = 2.6V DC
· min = 6.8 mA
The minimum resistor (R) value depends on the current sinking capability of the encoder.
VS
A1(+)
A1(–)
B1(+)
B1(–)
Z1(+)
Z1(–)
+VDC
COM
VS
OUT
COM
OUT
COM
VS
OUT
COM
R
(1)
Discrete Device Wiring
Power
Supply
Module Inputs
Solid-State
Switch
Proximity Sensor
Photoelectric Sensor
with Open Collector
Sinking Output
Power Supply Voltage
Pull-up Resistor Value Max (R)
(1)
(1) Resistance values may change, depending upon your application.
5V DC 352 Ω
12V DC 1382 Ω
24V DC 3147 Ω
R
V
dcVmin–()
Imin
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