Symbol SE 923, Integration Manual

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A-2
SE-923 Scan Engine Integration Guide
A Character
This specification uses the word character to generalize a unit piece of information. This unit
could be in bit, byte, word, etc.
Data
The word Data is used when referring to a group of characters.
Tolerances
Unless otherwise noted, all numeric figures stated in this document have a tolerance of ± 5%.
Common Attributes
This section describes those requirements that are common to the decoder and the host.
Note: SIF is a half-duplex communication protocol. In order to maintain
proper communication, the requirements in this section must be met.
All SIF systems have four signal lines. Two are for handshaking and two are for transmitting
and receiving serial data.
Many communications packages do not properly use the handshaking lines for half duplex
communications. So, if you are using a PC communications package such as Windows
Terminal, you must disconnect the hardware handshaking lines from the interface.
The software application libraries included with the optional SE 1223 Developer’s Kit
provide code to perform proper handshaking.
Table A-1 lists the decoder’s signal lines, and Table A-2 lists the host’s signal lines.
Table A-1. Decoder Signal Lines
TXD Serial data transmit output. Drives the serial data receive input of the host.
RXD Serial data receive input. Driven by the serial data transmit output of the host.
RTS Request-to-send handshaking line (output). See The Decoder on page A-3.
CTS
Clear-to-send handshaking line (input). See
The Decoder
on page A-3
.