252Chapter 11 Data Formats of Barcode TypesCode 128SyntaxData StructureASCII DC4 n ... n DC4hex. 14 n ... n 14dec. 20 n ... n 20DescriptionWhile many barcode styles are limited to numbers, Code 128 can encodenumbers, letters, and other symbols commonly found on keyboards, such as@, # and %. The Code 128 barcode is similar to three barcodes in one. Thethree barcode styles are called Code A, Code B, and Code C. Each barcodestyle is designed to encode certain types of data in the most compact way.• Code A encodes uppercase alpha, numeric and control codes.• Code B encodes upper and lower case alpha and numeric codes.• Code C encodes digits in pairs.A single Code 128 barcode may consist of all three Code 128 barcode stylesA, B and C. The printer chooses the styles which result in the most compactCode 128 barcode for the data to be encoded. Do not be concerned aboutchoosing the correct barcode styles as this is done automatically.The ">" (greater than) symbol is a special character prefix. If a character withdecimal value less then 32 needs to be encoded (i.e., a control character),then send a ">" followed by the character that is decimal 64 higher then thecontrol code character.NOTE: Control characters conflict with DC4, SUB. These characters areencoded by using the ">" sign following a number that is 64 dec.higher than the control character.Figures/Characters (n) Start Code Stop CodeASCIITable 45 on page 253.None Nonehex.dec.
