User Guide

TR4090 USER’S GUIDE
____________________________________________________________________________________________________________________________
CHECKPOINT SYSTEMS, INC. CONFIDENTIAL AND PROPRIETARY INFORMATION, FOR INTERNAL USE ONLY.
Dwg. No. 265245 Rev. 00 Page 7
stored in non-volatile memory so that when the TR4090 is turned off and then back on, the last
set data rate will be the data rate at which the TR4090 will transmit tag data.
Example: To change the baud rate, at which the TR4090 transmits data, to 28.8k baud, the
HOST PC should send the command “
B3\n
” or “
b3\n
”. The TR4090 will then
respond with the message “
Baud rate is 28.8k
”.
6.0 ONLINE REQUEST COMMAND
The HOST PC can verify that the TR4090 is online by sending an upper case ‘
O
’ or a lower case
‘
o
’ followed by the new line character ‘
\n
’. If the TR4090 is online, it will respond by echoing
back the command; i.e., “
O\n
” or “
o\n
”.
7.0 COMMANDS FOR TELEC USE
The following commands are used to set up the TR4090 for TELEC testing. These commands are
sent by a HOST PC to the TR4090 via an RS-232 serial port.
7.1 TRANSMITTER IDENTIFICATION NUMBER
TELEC requires that every RF transmitter have an associated identification number that can
be transmitted on command or on power-up of the device. In normal operation, the TR4090
generates a continuous wave (CW) carrier; i.e., the transmitter part of the transceiver is not
usually modulated. Nevertheless, TELEC requires field measurements from the transmitter
when modulating. Therefore, the following functionality has been added for TELEC testing.
The modulation is 1 of 16 pulse-position-modulation (PPM) with the start pulse being
interpreted as zero.
7.1.1 Assigning And Storing The 32-byte ID
An upper case ‘
I
’ or lower case ‘
i
’ is sent first, followed by a
32 byte identification
number
, followed by a new line character ‘
\n
’. The 32 byte ID is stored in non-
volatile memory so that the TR4090 can be powered down without losing its ID
number.
7.1.2 RF Transmitting The 32-byte ID
An upper case ‘
T
’ or lower case ‘
t
’ is sent first, followed by an ASCII ‘
1
’ to
command the TR4090 to transmit (amplitude modulate the carrier) its identification
number at a data rate of
1.428kbps
. This should not be confused with transmitting
data over the serial port; i.e., the ‘t’ refers to an RF transmission.
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.
An upper case ‘
T
’ or lower case ‘
t
’ is sent first, followed by an ASCII ‘
2
’ to
command the TR4090 to transmit (amplitude modulate the carrier) its identification
number at a data 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.