Rockwell Automation 1771-ASB/E Remote I/O Adapter User Manual User Manual

Page 58

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4–2

Troubleshooting

Publication 1771-UM001A-US-P - February 2000

Table 4.A

Remote I/O System Troubleshooting Guide

Indicators

Active Adapter I/O

FaultRack

Description

Probable Cause

Recommended Action

On

Off

Off

Normal indication; remote adapter is

fully operational; processor is in Run

mode

Off

On

Off

Adapter crash.

RAM memory fault.

Watchdog timeout

Cycle power. Replace module if

problem reoccurs.

On

Blink

Off

Module placement error

I/O module in incorrect slot.

Place module in correct slot in chassis.

Blink in unison Off

Incorrect starting I/O group number

Error in starting I/O group number or I/O

rack address

Check dipswitch settings. Refer to table

3.B to verify acceptable beginning I/O

group number; set switches correctly

On

On

On

Module not communicating

Incorrect baud rate setting

Check dipswitch setting

Off

On

On

Module not communicating

Scan switch set for "all but last 4 slots" in

1/4 rack

Reset scan switch setting

Blink

Off

Off

Remote adapter not actively

controlling I/O (scanner to adapter

communication link is normal)

4

;

scanner manual or

autoconfiguration

8

was successful

Processor is in program or test mode

Scanner is holding adapter module in

fault mode;

Configuration mismatch

Place processor in Run mode.

Fault should be cleared by I/O scanner

Correct the configuration mismatch, i.e.

incorrect rack size, rack number

LEDs sequence on/off

from top to bottom

Module not communicating

Another remote I/O adapter with the

same address is on the link.

Correct the address.

Blink

alternately

Off

Adapter module not actively

controlling I/O

2

Adapter module in processor restart

lockout mode (adapter to scanner

link is normal)

5

Processor restart lockout switch on

chassis backplane switch assembly on

1

Depress reset button to clear lockout

feature or cycle power; if after repeated

attempts indicators are still blinking,

check:

pushbutton not wired properly to

field wiring arm

wiring arm not connected to

adapter module

adapter module was reset by

processor/scanner, then

immediately faulted

Off

Off

On

I/O chassis fault.

2

No communication

on link.

Problem exists between:

adapter and module in chassis; the

module will stay in fault mode until

fault is corrected

shorted printed circuit board runs on

backplane or I/O module

Cycle power to the chassis to clear a

problem resulting from high noise

3

remove and replace all I/O

modules one at a time

if problem does not clear,

something is wrong in chassis or I/O

module

Blink

Off

On

Communication on link. Chassis

violation.

Possible shorted backplane in chassis.

Excessive noise on backplane.

6

Identify source of noise. Suppress

output module inductive loads or noise

sources in proximity to output module

wiring. Target the problem by splitting

the rack into smaller racks.

Check chassis, Replace chassis as

necessary.

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