What is a message – Rockwell Automation 2755 AdaptaScan Software User Manual

Page 139

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10–2

Publication 2755-838

A message is a series of data strings that the Reader transmits when
bar code symbols are decoded. These fields contain decoded bar
code data and other information such as package count. Messages
are sent to a host at the end of a trigger or after a valid package.

The message format is shown below. The length of the fields
(number of ASCII characters) is shown in parentheses.

ASCII BAR CODE DATA

11. Counter (10)

8. Field Delimiter (0 or 1)

7. Bar Code Data or No-Read Message, 0 to 64 characters, including start,
stop, and check characters. Up to 64 characters will be sent for each field
read (fields separated by a delimiter). Codabar Stop Character follows
Codabar Check Characters, if sent.

4. Source (0 or 2) contains DeviceNet Address (MAC ID)

3. Field Delimiter (0 or 1)

2. Header Message (0 to 32)

1. Source Identifier (0 to 8)

9. Field Delimiter (0 or 1)

13. Transmission Check (0 to 2)

12. End Message (0 to 3)

5. Symbology (0 or 2)

6. Margin (0 or 2)

10. Scan Count (0 or 2)

Some fields are provided by the decoded bar code symbol.
However, most of the fields are specified by the Message Format and
Field Edit dialogs.

What is a Message?

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