National Instruments NI 17xx Figure2 -5 shows an example of connecting the quadrature encoder differential line drivers., Figure 2-6 shows the internal quadrature encoder/RS-422 input circuit.

Chapter 2 Power and I/O
NI 17xx Smart Camera User Manual 2-8 ni.com
Figure2 -5 shows an example of connecting the quadrature encoder
differential line drivers.
Figure 2-5. Connecting Differential Line Drivers
Figure 2-6 shows the internal quadrature encoder/RS-422 input circuit.
Figure 2-6. NI Smart Camera Quadrature Encoder Input Circuit
Phase A+
Phase A–
Phase A–
Phase A
Phase B+
Phase B–
Phase B–
Phase B
Encoder NI 17xx
Twisted
Pair
Twisted
Pair
+
–
Phase A–
Phase A+
+
–
Phase B–
Phase B+
+3.3 V
10 kΩ10 kΩ10 kΩ10 kΩ
7.5 kΩ7.5 kΩ7.5 kΩ7.5 kΩ
NI 17xx