Rockwell Automation 2755 Enhanced Decoder Series B - Manual (Page 186)

14–4 Display and System Configuration
Publication 2755-833
The decoder performance indicators and counters are updated on the
display once each second. Following is a description of each display
item.
Decoder Performance
(Scanner A and B)
In continuous mode, the performance indicators display the
percent of decoded scans for each scanner.
In triggered mode, the performance indicators display the
number of valid scans (up to 100) during a trigger active
period for Scanner A and Scanner B.
Note: The decoder performance will never exceed the
capture count if Send Message to Host is set to Immediately
After Valid Package.
Decoder performance indicators are useful during:
- initial setup (when the decoder is in continuous mode)
to determine the optimum location of the scanner relative
to the bar code labels.
- decoder operation to identify a decrease in performance.
For example, if the number of good reads drops
significantly, the label quality may have degraded or the
scan head window may require cleaning.
Note: If a buffer overflow occurs while collecting data for
the sample scans, the value 999 displays until the condition
is corrected. This occurs if host communications is
suspended.
Symbols Not Read
Counter
Displays the number of symbols not read in the triggered
mode of operation.
A no-read occurs when the decoder does not decode the
correct number of symbols on a package as defined by the
Symbols per Package parameter.
The counter increments for each symbol not read in a
package.
Package Counter Displays the number of packages detected by the decoder.
The package counter increments each time a trigger is
generated by the package detector, a host command, or the
internal timer. It also increments each time a package is read
in the continuous or continuous/unique operation modes.
Primary Counters
(1-8)
Displays the number of output conditions that occur for each
discrete output (1-8).
Each output counter increments when a TRUE condition
occurs for that output.