Serial data should be in the following format:
1 start bit, 8 data bits, no parity, 1 or 2 stop bits
9600bps
0V=low, 5V=high
STATUS pin can be connected to one of the port pins which can generate an interrupt on low-to-high
transition (e.g. RB0/INT pin in the PIC). This can be used to enter a receive sub-routine to download
data received from remote TDL2A. Therefore, the host does not need to wait in a loop for a packet.
Range test and site survey can be carried out by connecting an LED on the STATUS pin. Every time,
TDL2A is within range to receive valid data, the LED will flicker.
Interfacing RS232 port to TDL2A
Figure 7: TDL2A interfaced to an RS232 port via an RS232 line driver/receiver
STATUS pin in this can be connected to CTS, DSR and DCD pin to simulate a flow control signal.
TDL2A is capable of continuously streaming data at 9600bps. Therefore, STATUS pin is not asserted to
stop the Host from sending data as in normal RTS/CTS flow control method, but merely to warn the
host that there is already data in the receive buffer which need to be downloaded before sending any
more data.
Some DTE hosts assert DTR signal when they are active and this can be used via RS232 line receiver to
enable TDL2A. Otherwise the ENABLE must be physically pulled-low to activate the TDL2A.
NOTE:
An interface board (with MAX232 type buffer, 9 way D connector, 5V voltage regulator and SMA RF
connector) is available. This board is 61mm x 33mm in size.
Radiometrix Ltd
TDL2A Data Sheet
page 7
RADIOMETRIX [ RADIOMETRIX LTD ]
