Accessing the system fault and warning queues, Handling download service errors – Rockwell Automation 1336T Function Block Prog. Manual, Series A/B User Manual

Page 165

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6–3

Handling Exceptions — Faults and Warnings

1336 FORCE — 5.9 August 1995

Once a fault or warning occurs, the information about the fault is
maintained in BRAM until you clear the fault queue using a Clear
Fault Queue command. To clear the function block fault once you
have corrected the problem within the function block application,
perform one of the following tasks:

Issue a Clear Fault command.

Issue a drive reset command.

Cycle drive power.

The fault queue contains information for up to 32 faults. The
following information is also maintained for each fault:

a fault queue entry number to indicate the position of the fault in
the fault queue

a trip point (TP) to indicate which entry in the fault queue caused
the drive to trip (all faults displayed before the TP fault occurred
after the TP was logged)

a five character decimal fault code, which is covered later in this
chapter

the time and date that the fault occurred

descriptive fault text

all clear fault commands and the time when they were executed

You need to use the Fault Queue Entry Read service to access the
information in the fault queue. Refer to the PLC Communications
User Manual for more information about the Fault Entry Read
service.

Because the download operation is more complicated than most of
the block transfer services, it is more common to see faults/warnings
at this time. The download operation may require that multiple
messages be sent before initiating a compile operation. When an
application requires more than one message packet, the service
ensures that a compile operation does not begin until the last
required packet is received and acknowledged.

Accessing the System
Fault and Warning Queues

Handling Download
Service Errors

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