Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 117)

8–4 Configuration: Extended Match Table and Counters
Publication 2755-833
Used for verification of specific label information. The
corresponding output counter increments each time a match entry
occurs.
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Lot, which is an advanced capability available only in the
extended match code table, and not in the primary match code
table
When Lot is selected, the decoder will change the Mode
parameter to Match Entry, M, place into the extended match code
table entry the value of the first Interleaved 2-of-5 label it reads,
and increment the counter. If Any had been selected as the
Symbology, it will change to I 2-of-5. Every time the system
encounters a matching I 2-of-5 label it will then:
– Increment the counter
– Activate appropriate outputs. ➀
This will continue until the decoder encounters a Code 39 label
with the same value, at which point the system will:
– Reset the Mode to Disable
– Change the Symbology to Code 39
– Increment the counter a final time
– Activate appropriate outputs a final time. ➀
You can use multiple Lot entries, and have them running
independently of one another. The Lot parameter provides a level
of process monitoring and control sophistication required in only
a few applications, but highly valuable where needed to generate
statistical information.
For example, suppose extended match code table entry 1 is set up
for lot mode, with activation of output 4. If the first Interleaved
2-of-5 symbol read by the decoder has a value of 123456, then
the mode becomes Match Entry, and 123456 becomes the match
string.
Subsequent I 2 of 5 symbols with the same value will each
increment the counter in row 1, and activate output 4. The first
Code 39 symbol read that has the value 123456 will “close” the
lot, and change the Symbology value from I 2 of 5 to Code 39,
change M to D for the Mode, activate output 4 for the last time,
and increment the counter a final time. This “closed” lot will not
increment the counter or activate outputs for any I 2 of 5 or Code
39 symbols once the lot is closed. Instead, it will open a new lot if
one is available.