Encoder Terminal Blocks - National Instruments MID-7602 User Manual And Specifications

Use shielded, 20 AWG wire or larger for the motor power cable. If available, you should connect a case
ground wire to pin 3 (Ground/Shield) to avoid ground loops and signal noise problems. Case ground
connects to the motor housing, not to the motor power terminals.
The MID-7604/7602 contains bipolar chopper drivers. You must wire the stepper motors in a 4-wire
configuration as shown in Figure 4. You must isolate unused lead wires and leave them disconnected.
Refer to the Stepper Motor Configurations
connecting 6- and 8-wire motors and on the alternate half-coil configuration.
Caution Never connect unused center taps or winding terminals to pin 3 (ground) or to each other.

Encoder Terminal Blocks

For quadrature incremental encoder signals, each MID-7604/7602 axis has a separate 8-position
removable screw terminal block. Where applicable, the MID-7604/7602 accepts two types of encoder
signal inputs: single-ended (TTL) or differential line driver. You can accommodate open-collector
output encoders by using 2.2 k pullup resistors to +5 VDC.
Figure 5 shows the typical encoder wiring pin assignment for single-ended signal input.
Figure 6 shows the typical encoder wiring pin assignment for differential line driver signal inputs.
If the encoder cable length is greater than 3.05 m (10 ft), use encoders with line driver outputs for your
applications. Power for a +5 V encoder—generated by a power supply inside the MID-7604/7602—is
available on pin 7.
Note If you require other encoder power voltages, reference an external power supply to the Digital
Ground signal on the 8-pin encoder terminal block.
MID-7604/7602 Stepper Power Motor Drive User Guide
Encoder A
Encoder B
Encoder Index
Digital Ground
Figure 5. Typical Single-Ended Encoder Wiring Pin Assignment
Encoder A
Encoder A
Encoder B
Encoder B
Encoder Index
Encoder Index
Digital Ground
Figure 6. Typical Differential Line Driver Encoder Wiring Pin Assignment
section of this guide for additional information on
1
2
3
4
5
6
+5 V
7
8
1
2
3
4
5
6
+5 V
7
8
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