Gasboy SCII POS - Manual (Page 69)

62 Disk journal layout Point of Sale and Shift Change
Gasboy CFN Series 03/07/03
FIELDS IN ALL RECORDS
All records are separated by a carriage-return and linefeed. All records start with the following
information:
• checksum type
• checksum
• record sequence number
• record class
• record subclass
• record revision level
• site ID
Checksum type and checksum
The first character in each record is the checksum type. All records are of checksum type S. A
checksum of type S is a three-digit decimal arithmetic checksum on all fields following the
checksum, including the record separator (the carriage-return and linefeed).
The checksum is calculated by summing the ASCII values of each character, then expressing the
sum as three decimal digits using the modulus operator.
Record sequence number
Each record has a sequence number, a serial number that ranges from 1 to 99999. The sequence
number of the first record in the disk journal can be any value: each subsequent record in the disk
journal has a sequence number that is one plus the sequence number of the previous record. The
number rolls over at 99999 to 00001.
Since there is no limit to the number of records in a disk journal, the sequence number can
uniquely identify records in disk journals with up to 99,999 records.
Record class, subclass, and revision level
Each type of record in the journal file can be uniquely identified by three fields:
• a class (either transaction or event),
• a subclass (collectively called the record type), and
• a revision level (starting with 1). The revision level of each record type starts at 1 and is
incremented independently for each record type whenever the record format is changed for
that type. Revising a particular record type results in the revision level for only that record
type being incremented.
The class and subclass collectively are called the record type. Supported values for class/ subclass
are:
• T Transaction: records sales or any action affecting sales totals. The transaction subclasses
are:
• H Header: device, date, time, shift, total amount, etc. One record per transaction.
• F Fuel detail: fuel item of a sale. Optional. At most, one record per transaction.
• M Merchandise detail: non-fuel item of sale. One record for each merchandise line on sale.
• A Authorized tender detail: method of payment. One record for each type of authorized tender
used on sale. Only one type of tender is allowed per sale.
• L Legal tender detail: method of payment. One record for each type of legal tender used on
sale. Only one type of tender is allowed per sale.
• P Patronage tender detail: method of payment. One record for each type of patronage tender
used on sale. Only one type of tender is allowed per sale.