Rules Hierarchy (In Bar Codes) - Symbol LS 3408 Product Reference Manual

the "sale" rule above, the rule programmer wants the cashier to scan the bar code "M" before a sale.
To do this, a rule can be entered as follows:
When scanning a bar code of length 1 that begins with "M", select rule set number 1.
Another rule could be programmed to switch back.
When scanning a bar code of length 1 that begins with "N", turn off rule set number 1.
The switching back to normal rules can also be done in the "sale" rule. For example, the rule may look
like this:
When scanning a bar code of length 15, send the next 2 characters, send the class key, send the
next 8 characters, send the stock key, turn off rule set 1.
It is recommended that the
programming a rule belonging to an alternate rule set.
In addition to enabling and disabling rule sets within the rules, it is possible to enable or disable them
by scanning the appropriate bar codes on 14-11.

Rules Hierarchy (in Bar Codes)

The order of programming individual rules is important.The most general rule should be programmed
last.
All programmed rules are stored in a buffer. As they are programmed, they are stored at the "top" of
a rules list. If three rules have been created, the list would be configured as follows:
Third Rule
Second Rule
First Rule
When data is scanned, the rules list is checked from top to bottom to determine if the criteria matches
(and therefore, if the actions should occur). Input is modified into the data format specified by the first
matching set of criteria it finds. Be sure that the most general rule is the last one programmed.
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.
Disable All Rule Sets bar code on page 14-11 be scanned after
Advanced Data Formatting
14-7