Link termination -4, Link termination, 1/2 watt – Rockwell Automation 1747-ASB Remote I/O Adapter User Manual

Page 82

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Publication 1747-UM006B-EN-P - June 2003

5-4 Installation and Wiring

Link Termination

A 6-pin keyed connector provides a quick connection to the RIO link
and processor restart lockout switch. A user-supplied terminating
resistor must be attached across line one and two of the connector at
each end of the RIO link. The

size of the resistor depends on the

baud rate and whether the scanner and all adapters have extended
node capability, as shown in the table below. The cable shield must
be connected to chassis ground only at one end of the RIO link.

Baud Rate

Terminating Resistor Size

Using Extended Node Capability

All Baud Rates

82

1/2 Watt

Not Using Extended Node Capability

57.6K baud

150

1/2 Watt

115.2K baud

150

1/2 Watt

230.4K baud

82

1/2 Watt

IMPORTANT

If the signal integrity on the RIO link is compromised
by environmental noise, improper termination,
and/or improper cable installation, the 1747-ASB
module scan rate drops. This is indicated by a
pronounced flickering of the status display.

ADAPTER

Blue

Clear

Shield

1
23

45

6

7

8

SW1

1 2

3

45

67

8

SW2

1 2

3

4

5

67

8

SW3

O

N

O

N

LINE 1

SHLD
LINE 2
NC
IN
RET

(MSB)

LOGICAL
RACK

(LSB)

LOGICAL

GROUP

BAUD
RATE

PRI/COMP

RSV
(MSB)

(LSB)

IMAGE
SIZE

HLS
PRL

RESP

LAST CHA

ADDR
MODE

SP MODE

KEY

1747–ASB

ST ATUS

COMM F AUL T

LINE 1 (Blue wire)

SHLD (Shield wire)
LINE 2 (Clear wire)

NC (No Connect)

IN

RET

To Scanner’s
Connector

Chassis Ground

Terminating Resistor

Terminating Resistor

Status Display

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