Barcode Scanning

Scanners with bidirectional interface (such as the one integrated in the MC3090 Handheld Computer) get programmed automatically by BPS.

Scanners looped into the keyboard stream need to be programmed manually before using them with BPS. The scanner should send STX CI DATA ETX, where STX is Ctrl-B, CI is the Code Identifier from the table below, DATA is the scanned data (either with or without check char, see notes in table below), and ETX is Ctrl-C.

For testing it is useful when scanner input can be simulated by normal keyboard strokes. However BPS expects that the scanner input introduced by STX is completed by ETX within a certain period, and times out after reaching the limit reverting back to regular keyboard operation. This timeout, normally a few seconds, can be increased in the BPS settings if you want to simulate the scanner input. In the folder

  Central System Settings
      Scanning
          Keyboard
          

is the key Timeout. The period in seconds can be adjusted so you can comfortably enter the record manually for the tests. On a production PC the timeout should be set back to a few seconds after completion of the tests.

The application needs to know, which bar code type should be accepted for a certain data type. These informations are stored in the BPS settings in the following folder:

  Central System Settings
      Scanning

Within this folder, the key Display time gives the number of seconds to display the scan result when picking.

The other keys define what codes shall be accepted as a certain content. Each of the values may be a single code, or comma separated list of codes to accept.

Examples:

While the AI of EAN 128 is obvious, the use of a value in paranthesis after other code types, as in the third example, needs some explanation: The lowest two digits (unit and ten's place) define the number of characters to extract, and the upper digits specify the starting index (0 based). So a value of 1020 means “start at position 10 and return 20 characters” and a value of 5 means “start at position 0 and return 5 characters”.

Examples:

Notes:

(1) Check char transmitted
(2) Check char not transmitted
(3) Set of 43 chars encoded: 0…9 A…Z - . SPACE $ / + %
(4) Set of 128 chars encoded: ASCII 0…127. FNC1 encoded as GS (Ctrl-])
(5) Application Identifier added in parentheses to the BPS name, for example EAN128(91) = AI 91

AI:
x = digit for length indication
y = digit for decimal point indication

Type:
n = numeric (0-9)
a = alphanumeric

FNC1:
no = never, always all length used
yes = only if content is shorter than maximum length and not last AI of the code