User Guide

TR4090 USER’S GUIDE
____________________________________________________________________________________________________________________________
CHECKPOINT SYSTEMS, INC. CONFIDENTIAL AND PROPRIETARY INFORMATION, FOR INTERNAL USE ONLY.
Dwg. No. 265245 Rev. 00 Page 8
An upper case ‘
T
’ or lower case ‘
t
’ is sent first, followed by an ASCII ‘
3
’ to
command the TR4090 to transmit (amplitude modulate the carrier) its identification
number at a data rate of
357bps
.
The symbol rate is therefore 1 symbol/11.2msec which gives 700usec/pulse
position. The pulse width is ½ the pulse position time which is 350usec.
7.1.3 Reporting The 32-byte ID
An upper case ‘
R
’ or lower case ‘
r
’ is sent by the HOST PC to command the
TR4090 to report its identification number back to the HOST PC via the RS-232
serial port.
7.2 PSEUDO NOISE TRANSMITTER
The pseudo noise transmitter is a TELEC requirement. The pseudo noise polynomial is
1 + X
14
+ X
15
. The pseudo noise is a pseudo-random sequence of 1 of 16 PPM data.
The following commands are used to start the pseudo noise generator. NOTE: TAGS
CANNOT BE READ WHILE TRANSMITTING PSEUDO NOISE.
7.2.1 Generating/Transmitting The Pseudo Noise
An upper case ‘
N
’ or lower case ‘
n
’ is sent by the HOST PC, followed by an ASCII
‘
1
’, to command the TR4090 to transmit (amplitude modulate the carrier) a
“random” sequence of PPM data at a rate of
1.428kbps
. The symbol rate is
therefore 1 symbol/2.8msec which gives 175usec/pulse position. The pulse width is
½ the pulse position time which is 88usec.
The pseudo noise data stream will be continuously transmitted until the command is
given to stop transmitting. An ASCII ‘
N
’ or ‘
n
’ is sent to STOP the pseudo noise
generator. The TR4090 will then be ready to read tag data without having to restart
the GPR.
An upper case ‘
N
’ or lower case ‘
n
’ is sent by the HOST PC, followed by an ASCII
‘
2
’, to command the TR4090 to transmit (amplitude modulate the carrier) a
“random” sequence of PPM data at a rate of
714bps
. The symbol rate is therefore
1 symbol/5.6msec which gives 350usec/pulse position. The pulse width is ½ the
pulse position time which is 175usec.
An ASCII ‘
N
’ or ‘
n
’ is sent to STOP the pseudo noise generator.
An upper case ‘
N
’ or lower case ‘
n
’ is sent by the HOST PC, followed by an ASCII
‘
3
’, to command the TR4090 to transmit (amplitude modulate the carrier) a
“random” sequence of PPM data at a rate of
357bps
. The symbol rate is therefore 1
symbol/11.2msec which gives 700usec/pulse position. The pulse width is ½ the
pulse position time which is 350usec.
An ASCII ‘
N
’ or ‘
n
’ is sent to STOP the pseudo noise generator.
Summary of Commands For Transmitting ID and Pseudo Noise
Note: All commands are in ASCII format so that ‘1’ = 0x31 for example.
ACTION HOST PC Command