Rockwell Automation 1336T Function Block Prog. Manual, Series A/B - Manual (Page 166)

6–4 Handling Exceptions — Faults and Warnings
1336 FORCE — 5.9 August 1995
After receiving the last packet, the drive performs a series of checks
to verify the new execution list:
❒
The drive goes over the execution list and verifies the checksum.
If the checksum fails, the service fails.
❒ The drive checks that any new events with block numbers that
match block numbers found within the current application have
the same block type. If the block number verification fails, the
service fails.
❒ The service verifies that the block type numbers are within the
valid range.
❒
The service verifies that events with a zero for a block ID have a
zero value for a block type number and that events with a zero for
a block type number have a zero for a block ID.
When the download service fails, the following steps are taken:
1. Download failures will NAK (Not AcKnowledge) the service, but
will not fault the drive nor interrupt the currently running
function block application.
2. Download failures will reset the service to allow it to accept
another download and compile attempt.
3. Values from the currently valid function block application
overwrite the execution list.
4. One of the following warnings will be logged:
Warning Description
FB DNLD Bad Evnt An attempt was made to download a bad execution list.
FB BAD Pkt Num The service received a bad packet number.
FB DNLD Blk# Wrn An invalid block number was received.
FB DNLD Cksm Wrn The execution list did not pass the checksum test.
When a new execution list has been downloaded and all the service
checks have been passed:
❒
The currently active application is taken off line.
❒ The compiler is initiated as a background process.
❒
The function block task status indicates that a compile is in
process.
Compile time errors will soft fault the drive.
Even though it is unlikely that you will receive a fault once the event
list has passed the service checks, several faults are possible.
Handling Compile Faults