Opticon XPT 3125 Universal menubook - Manual (Page 142)

Appendix
OPTICON Universal menu book
U135
Reader:
A device that examines a spatial pattern, one
part after another, and generates analog or
digital signals corresponding to the pattern.
The reader converts bar code symbols to
electrical signals for input to a bar code reader
decoder for processing and subsequent output
through a data communications interface.
RS232:
A standard for serial communication between
two devices. The serial communication consists
of data transfer and handshaking. The exact
data format and protocol are not defined by this
standard. All Opticon products use ASCII for
the data format. All handheld and stationary
readers use plain text protocol. Opticon
terminals are free to implement any protocol.
Scan engine:
The scan engine consists of an illumination part
(optional), a sensor part and a digitizer part.
With this, it translates a printed bar code into a
computer readable form. The scan engine uses
one of the following techniques: laser, CCD or
CMOS.
Scan rate:
The number of scans (the attempts to
recognise a barcode symbol optically) per time
unit.
Scanner:
See Scan engine.
Start bit:
A control bit used to indicate the start of a
group of data bits being sent in asynchronous
transmission.
Stop bit:
A control bit used to indicate the end of a group
of data bits being sent in asynchronous
transmission.
Structured append:
The possibility to concatenate multiple bar
codes into one block of data. This method is
supported by most 2D bar codes.
Suffix:
One or more characters which accompany
transported data. A suffix is put at the end of
the data and is part of the frame.
Symbology:
A set of rules specifying the way in which data
may be represented.
Trigger:
A signal that initiates an action or a series of
events. The trigger button on a bar code reader
will start the scan-engine and try to decode the
scanned and digitized data.
TTL interface:
A serial interface that typically is used between
embedded devices. The TTL standard defines
a logical "1" level at 5 volt.
USB:
An acronym for Universal Serial Bus. This bus
allows for multiple and different devices to
connect to a single host, like a computer.
VCP:
An acronym for Virtual Communications Port.
This will emulate the RS232 port for the USB
interface.