There is huge zoo of these
devices. They are divided to different groups from marketing and user
point of view. In this post I'd like to introduce you a third point
of view. Point of view of software engineer.
1. Quick start
Bar-code reader is always
read only device for PC.
Bar-code reader could be
configured via scanning special bar-codes from it's user manual
You can configure many
parameters in that way. The most interesting for us are prefix and
suffix of code sequence (I'll back to this later in details)
2. Two kinds of bar-code readers
I divided our bar-code
readers zoo in two parts: 1. Bar-code readers that interact with PC
like HID devices (these includes PS/2 and USB bar-code readers); 2.
Bar-code readers that connects via RS-232 port.
Both of these kinds of
devices have their advantages and disadvantages.
2.1. HID devices
Pros:
+ Easy to prepare your
program to work with them.
+ You have no need to
handle reconnection issues and the like.
Cons:
- There is sometimes hard
to determine if we have input from bar-code reader or from keyboard
(but this can be solved by using a prefixes and suffixes).
2.2. RS- 232 devices
Pros:
+ You always know that
input that you receive is from bar-code reader.
Cons:
- You should handle
reading from RS-232 port in your program.
- You should handle
connection issues in your program.
3.N.B.
If you make some mistakes
in configuration of bar-code readers, there is a page with “reset
to factory defaults” sequence in user manual (Check if you have
this page before making any changes in configuration).
