User's Manual

15 - 4 Symbol DS6878 Product Reference Guide
and the cashier keys the price manually.
To implement this, first enter an ADF rule that applies to the normal situation, such as:
Scan Rule Belongs to Set 1. 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, send the data that remains, send the Enter key.
The “sale” rule may look like this:
Scan Rule Belongs to Set 2. 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.
To switch between the two sets of rules, program a “switching rule” that specifies what type of bar code to scan to
switch between the rule sets. For example, in the case of 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.
Program another rule to switch back.
When scanning a bar code of length 1 that begins with “N”, turn off rule set number 1.
Or include the switching back to normal rules in the “sale” rule:
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.
For optimal results, scan the Disable All Rule Sets bar code on page 15-10 after programming a rule belonging to
an alternate rule set.
In addition to enabling and disabling rule sets within the rules, enable or disable them by scanning the appropriate
bar codes on page 15-10.
Rules Hierarchy (in Bar Codes)
The order of programming individual rules is important.Program the most general rule first.
All programmed rules are stored in a buffer. As they are programmed, they are stored at the “top” of a rules list. If
you create three rules, the list is configured as follows:
Third Rule
Second Rule
First Rule
When you scan data, the rules list is checked from top to bottom to determine if the criteria matches (and therefore,
if the actions occur). Input is modified into the data format specified by the first matching set of criteria it finds. 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 the SECOND rule appears to not
function.