Interface cable examples, With pull-up resistors – Rockwell Automation 1398-DDM-xxx USE MNL/ULTRA 200 DIG.SERVO.DR User Manual

Page 85

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Publication 1398-5.0 – October 1998

Interfaces

6-21

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.

To improve noise immunity, a cable shield should terminate at both
ends of the cable. Shields should connect to the backshell of the
connectors with termination around the full circumference (360°). The
connectors should attach to chassis ground (not signal common).

Figure 6.23

External Encoder Interface via TTL Differential Line Drivers

Figure 6.24

Complementary Encoder Interface via 7406 Line Drivers
with Pull-up Resistors

Ch A

ENCODER

AX+
AX-

14
15

J1

Drive

twisted pair

Ch B

BX+
BX-

16
17

twisted pair

Ch I

IX+
IX-

18
19

twisted pair

Drive Chassis

Encoder Case

2

4

+5V

Supply
Return

+5 Volts

1

3

+5V

Supply

+5VDC

5V @ 250 mA

ECOM

twisted pair

For horizontal dashed lines,
connect only if J1 sources Encoder power

ENCODER

J1

Drive

Ch B

BX+
BX-

16
17

twisted pair

Drive Chassis

Encoder Case

+5 Volts

7406

Ch A

AX+
AX-

14
15

+5 Volts

7406

Ch I

IX+
IX-

18
19

+5 Volts

7406

twisted pair

twisted pair

twisted pair

2

4

+5V

Supply
Return

+5 Volts

1

3

+5V

Supply

+5VDC

5V @ 250 mA

ECOM

For horizontal dashed lines,
connect only if J1 sources Encoder power

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