Interface cable examples, Auxiliary encoder input circuit – Rockwell Automation 1398-DDM-xxx ULTRA 100 Series Drives Installation Manual User Manual

Page 85

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Publication 1398-5.2 – PDF 1997

Interfaces

6-21

Step and direction signals, such as those created by indexers for step
motors

CW (Step Up)/CCW (Step Down) signals, typically used with stepper
indexers.

The input circuits shown in the following diagrams support
connections to differential TTL line drivers, single-ended TTL line
drivers and open collector devices. These inputs are under software
control.

Interface Cable Examples

The use of differential signals is highly recommended. This is due
to the immunity of differential signals to common mode interference.
Single-ended encoder interface circuits are not recommended, and
may result in system malfunction.

Note: The use of differential signals is strongly recommended. Single-
ended signals are susceptible to noise, which may cause intermittent or
continuous errors.

Note: To improve noise immunity, terminate cable shields at both ends
of the cable. Connect shields to the backshell of the connector with a
complete circumferential (360°) termination. The cable connector
should then connect to chassis ground (not signal ground).

Figure 6.24

Auxiliary Encoder Input Circuit

-

+

26LS33

AX(-)

1K

220pF

AX

220pF

AX(+)

1K

5K

+5VDC

10K

+5VDC

10K

5VCOM

Drive

J1

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