Publication 1746-5.16
17
Single-Ended Encoder Wiring (Sourcing)
(4) The Allen-Bradley 845H sourcing encoder is not compatible with this module.
VS Value
R Value
Maximum Output Leakage
+5V dc
no resistor needed
6.3 µA
+12V dc
1800 ohm 1/4W 5%
1.5 µA
+24V dc
4700 ohm 1/4W 5%
1.2 µA
R
R
A
Z
A(+)
A(±)
B(+)
B(±)
Z(+)
Z(±)
B
1234
R
Belden 9503 or equivalent
305m (1000tft) max length
Power
Supply
+ VDC
COM
VS
GND
Shield
(2)
Module Inputs
SW1
ON
OFF
(All switches OFF)
cable
(1)
single ended
encoder
(4)
(1) Refer to your encoder manual for proper cable type and length.
(2) Due to the topology of the module’s input circuits, terminating the shield at the encoder end
provides the highest immunity to EMI interference. Connect EARTH ground directly to the
encoder connector housing.
(3) The resistor (R) value depends on the power supply value (VS). The table below lists the
resistor values for typical power supply values. These resistors must be located at the encoder
end of the cable.
(3)
(3)
(3)
A
B
Z
Single-Ended Encoder Output Waveforms
The figure below shows the single-ended encoder output waveforms. When the waveform is low, the
encoder output transistor is OFF.
low = transistor OFF
high = transistor ON
Allen-Bradley HMIs