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Data Editing Formulas
The set of instructions programmed into the reader to define data fields
and than arrange them into a format is known as the data editing
“formula.”
A maximum of four formulas can be resident in the reader’s memory at any
one time. If more than one formula is stored in memory, the reader will
apply the first formula to the decoded data. If the data format matches the
format (credit card, driver’s license, etc.) of the first formula, then it will
re-arrange, add, and drop the data fields as you have indicated and
output the reformatted data to the host.
However, if the data does not match the criteria spelled out in the first
formula, then the criteria of the second formula stored in memory will be
applied. And so on. This process will continue for each of the successive
formulas until a match is found. If no matches are found for any of the
formulas programmed into the reader, then the unedited data record will
not be transmitted to the host by default.
The number of formulas the reader will store is limited by the amount of
memory available. Caution should therefore be used when entering a
number of long formulas, as all might not fit.
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Data Fields
By separating decoded data into blocks known as “fields,” each block of
data can be treated individually. Fields can also be added to the data,
permitting user-required characters or function keys to be included.
The fields are identified by a one-character ID starting with the character
“A” (up to and including “Z”) in the order they were created. These fields
can then be sent to the host in the order you specified.
For example, if the credit card data on Track 2 of the magnetic stripe is:
;1234567890123456=9912xxxxxxx?
It is divided into seven fields (A, B, C, D, E, F, and G) as shown below:
;1234567890123456=9912xxxxxxx?
|A| B |C| D | E |F|
If your application software needs the data sent in the following format:
9912<ENTER>
1234567890123456<ENTER>
You can create that format by selecting only the fields you need,
reversing the order in which they are sent to the host, and then creating a
new field <ENTER> to insert after each field.
We do this by using the fields as defined above and adding a new field:
Field B = 1234567890123456
Field D = 9912
Field G = <ENTER>
and then sending {Field D}{Field H}{Field B}{Field G} to the host.
