User Guide

TR4090 USER’S GUIDE
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CHECKPOINT SYSTEMS, INC. CONFIDENTIAL AND PROPRIETARY INFORMATION, FOR INTERNAL USE ONLY.
Dwg. No. 265245 Rev. 00 Page 6
ASCII data, and an end character which is an ASCII capital ‘N’. All characters are therefore
ASCII and so can easily be viewed using HyperTerminal for example.
For example, the data read by the Reader will be of the form:
Preamble Header User Data CCITT-16 CRC Unused memory
0xFF 0x11 15 bytes 2 bytes 2 bits
and the data sent out by the Reader to the HOST will be of the form:
ASCII Start Charcter User Data ASCII End Character Total Bytes Sent to
HOST
‘X’ 30 bytes ‘N’ 32 bytes
4.0 CONVERTING ASCII REPRESENTATION TO BINARY
To convert from ASCII to BINARY, the HOST PC should subtract 0x30 for characters between
‘0’ and ‘9’, and should subtract 0x37 for characters between ‘A’ and ‘F’.
Note that the values 1010 = 0xA through 1111 = 0xF are converted by the reader to UPPER
CASE ‘A’ through ‘F’ and so 0x37 must be subtracted not 0x57 which corresponds to a lower
case ‘a’.
Example:
Tag Data:
0x1, 0xA, 0x2, 0xB …
Data sent by TR4090 to HOST PC:
0x31, 0x41, 0x32, 0x42 …
To convert to binary:
0x31 – 0x30 =
0x1
, 0x41 – 0x37 =
0xA
, 0x32 – 0x30 =
0x2
, 0x42 – 0x37 =
0xB
….
5.0 BAUD RATE SELECTION COMMANDS
The rate at which data is
transmitted
from the TR4090 to the HOST PC is selectable. The data
rate is selected by the HOST PC by sending the following commands to the TR4090 from the
HOST PC at 9600 baud:
HOST PC Command TR4090 Response – Change Transmit Baud Rate
To:
“B1\n” or “b1\n” 9600 baud
“B2\n” or “b2\n” 19.2k baud
“B3\n” or “b3\n” 28.8k baud
“B4\n” or “b4\n” 38.4k baud
The TR4090 responds by sending the character string “
Baud rate is
” followed by the baud rate
value such as “
28.8k
”. This string is sent by the TR4090 to the HOST PC at the new baud rate.
Once set, the TR4090 will send tag data to the HOST PC at this data rate. The data rate is also