AeroComm Corporation LX2400 Manuel D’Utilisation
THEORY OF OPERATION
09/22/00
Preliminary
Preliminary
9
3. Theory of Operation
3.1 Interface Signal Definition
The LX2400S has a simple interface that allows OEM Host communications with the transceiver. Table 1
shows the connector pin numbers and associated functions. The I/O direction is also shown. The direction
is with regard to the transceiver. All I/O is 5Vdc TTL level signals except for RSSI. All outputs are weakly
pulled high (20k – 50k ohms) when left unconnected and are driven high at reset.
shows the connector pin numbers and associated functions. The I/O direction is also shown. The direction
is with regard to the transceiver. All I/O is 5Vdc TTL level signals except for RSSI. All outputs are weakly
pulled high (20k – 50k ohms) when left unconnected and are driven high at reset.
Table 1 – Connector J1 Pin Definitions
Pin
TYPE
Signal Name
Function
1
O
DCD
Not Implemented
2
O
TXD
Transmitted data out of the transceiver
3
I
RXD
Data input to the transceiver
4
I
DTR
Not Implemented
5
GND
GND
Signal Ground
6
O
DSR
HOP FRAME/Data Set Ready – Active Low when the transceiver is
hopping.
hopping.
7
O
CTS
Clear to Send – Active Low when the transceiver is ready to accept data
for transmission. This is in response to a valid TE signal. A Client will not
respond with CTS if it is not in range of a Server.
for transmission. This is in response to a valid TE signal. A Client will not
respond with CTS if it is not in range of a Server.
8
I
RTS
Not Implemented
9
O
RI
Not Implemented
10
PWR
VCC
5V + 2%
11
PWR
VCC
5V + 2%
12
I
TST_MODE
Test Mode
1. When pulled low before applying power the transceiver’s serial
interface is forced to a 9600,8,N, 1 rate.
2. When pulled low and the CONFIGURATION START BYTE
command (See 3.2.6.2.1) is sent to the transceiver, Configuration
Mode is entered to read and write parameters in EEPROM
Mode is entered to read and write parameters in EEPROM
13
O
RSSI
Received Signal Strength - An analog output giving a relative indication of
received signal strength while in RECEIVE MODE.
received signal strength while in RECEIVE MODE.
14
I
WR_ENA
EEPROM Write Enable – When pulled low it allows the Host to write the
on-board EEPROM.
on-board EEPROM.
15
I
UP_RESET
RESET – Controlled by the LX2400S for power-on reset if left
unconnected. After a Stable power-on (4ms ) A 10us high pulse will reset
the LX2400S.
unconnected. After a Stable power-on (4ms ) A 10us high pulse will reset
the LX2400S.
16
GND
GND
Signal Ground
17
I
TE
Transmit Enable – When pulled low, the transceiver switches to transmit
mode and will respond with CTS when data can be transmitted by the
Host.
mode and will respond with CTS when data can be transmitted by the
Host.
18
I
RE
Radio Enable – When the RADIO_ENABLE_ENABLED control bit is set
in EEPROM the transceiver will only allow Host communications/control
when this line is pulled low. If the RADIO_ENABLE_ENABLED control
bit is cleared, the transceiver ignores this input.
in EEPROM the transceiver will only allow Host communications/control
when this line is pulled low. If the RADIO_ENABLE_ENABLED control
bit is cleared, the transceiver ignores this input.
19
O
PLL_LOCK
Factory Use Only – NC
20
O
IN_RANGE
In Range – Active Low when a Client radio is in range of a Server on the
same channel.
same channel.
I = Input to the transceiver
O = Output from the transceiver
O = Output from the transceiver