Advanced Data Formatting 15 - 5
Rules Hierarchy (in Bar Codes)
When programming rules, be sure to program the most general rule first, as rules are stored at the “top” of a rules
list in a buffer as they are entered. For example, if you create three rules, the list is configured as follows:
Third Rule
Second Rule
First Rule
After scanning data, the rules hierarchy checks the rules list from top to bottom to determine if the criteria matches
(and therefore, whether to apply the actions). Actions modify the data format specified by the first matching set of
criteria it finds, then disregard subsequent rules. For this reason, be sure to program the most general rule first.
For example, if the THIRD rule states:
When scanning a bar code of any length, send all data, then send the ENTER key.
and the SECOND rule states:
When scanning a Code 128 bar code of length 12, send the first four characters, then send the ENTER key,
then send all remaining data.
and you scan a Code 128 bar code of length 12, the THIRD rule applies and th e SECOND rule does not function.
Note standard data editing functions (scan options) are considered ADF rules, and the previous hierarchy applies
to them. Scan options include prefix/suf fix programmin g in the parameter Scan Data Transmission Format on page
14-5. These rules reside in the same “rule list” as ADF rules, so the order you create them is also important.
Default Rules
Every scanner has a default rule to send all scan data. Scanners with custom software may have one or more
default rules burned in. Th e rules hierar chy checks user progr ammable rules first, then th e default rules. To disable
default rules enter the following general rule in the user programm able buffer:
When receiving scan data, send all data.
Since this rule always applies, ADF never applies the default rules.
Special Considerations for Multipoint Networks
ADF rules scanned by an ind ividu a l sc anne r ar e NOT broadca st to ot he r sca n ne rs in the pic on et , as ar e oth e r
parameters; however, ADF rules that 123Scan generates ARE broadcast to all scanners in the piconet. 123Scan
rules transmitted from the base are stored at the BEGINNING of the ADF rule buf fer, regardless of the presence of
existing rules, while rules scanned by the scanner are appended to the existing buffer. For this reason, transmit
rules to be shared by all scanners from 123Scan FIRST. Then, scan rules to customize an individual scanner.