AeroComm Corporation 44249AJ Manuale Utente
5
5
5
5////8/2007
8/2007
8/2007
8/2007
10
10
10
10
3.
3.
3.
3. Specifications
Specifications
Specifications
Specifications
3.1
3.1
3.1
3.1 IIII
NTERFACE
NTERFACE
NTERFACE
NTERFACE
S
SS
S
IGNAL
IGNAL
IGNAL
IGNAL
D
D
D
D
EFINITIONS
EFINITIONS
EFINITIONS
EFINITIONS
The AC4424 has a simple interface that allows OEM Host communications with the
transceiver. Table 1
transceiver. Table 1
Table 1
Table 1
Table 1 –––– Pin Definitions
Pin Definitions
Pin Definitions
Pin Definitions, shows the connector pin numbers and associated
functions. The I/O direction is with regard to the transceiver. All I/O is 5VDC TTL level signals
except for RSSI. All inputs are weakly pulled High and may be left floating during normal
operation.
except for RSSI. All inputs are weakly pulled High and may be left floating during normal
operation.
Table
Table
Table
Table 1
1
1
1 –––– Pin Definitions
Pin Definitions
Pin Definitions
Pin Definitions
Pin
Pin
Pin
Pin
Type
Type
Type
Type
Signal Name
Signal Name
Signal Name
Signal Name
Function
Function
Function
Function
1
NC No
Connect
2
O
TXD
Transmitted data out of the transceiver
3
I
RXD
Data input to the transceiver
4
NC No
Connect
5 GND
GND Signal
Ground
6
O
Hop Frame
HOP FRAME – Active Low when the transceiver is hopping.
7
O
CTS
Clear to Send – Active Low when the transceiver is ready to accept data for
transmission.
transmission.
8
I
RTS
Request to Send – When enabled in EEPROM, active Low when the OEM Host is ready
to accept data from the transceiver. NOTE: Keeping RTS High for too long can cause
data loss.
to accept data from the transceiver. NOTE: Keeping RTS High for too long can cause
data loss.
9
NC No
Connect
10
PWR
VCC
5V ± 2%, ± 50mV ripple
11
PWR
VCC
5V ± 2%, ±50 mV ripple
12 I/O 9600_BAUD/
Packet Frame
9600_BAUD – When pulled logic Low before applying power or resetting the
transceiver’s serial interface is forced to a 9600, 8, N, 1 rate. To exit, transceiver
must be reset or power-cycled with 9600_Baud logic High.
*Note:
transceiver’s serial interface is forced to a 9600, 8, N, 1 rate. To exit, transceiver
must be reset or power-cycled with 9600_Baud logic High.
*Note:
*Note:
*Note:
*Note: 9600_BAUD should only be used to recover the radio from an unknown baud
rate and should not be used during normal operation.
Packet Frame – When programmed in EEPROM, Packet Frame will transition logic Low
at the start of a received RF packet and transition logic High at the completion of the
packet.
rate and should not be used during normal operation.
Packet Frame – When programmed in EEPROM, Packet Frame will transition logic Low
at the start of a received RF packet and transition logic High at the completion of the
packet.
13
O
RSSI
Received Signal Strength Indicator - 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 logic Low, it allows the Host to write the on-board
EEPROM. Resetting the transceiver with this pin pulled Low may corrupt EEPROM
data.
EEPROM. Resetting the transceiver with this pin pulled Low may corrupt EEPROM
data.
15
I
UP_RESET
RESET – Controlled by the AC4424 for power-on reset if left unconnected. After a
Stable power-on (250ms) a 50us logic High pulse will reset the AC4424. Do not
power up the transceiver with this pin tied Low.
Stable power-on (250ms) a 50us logic High pulse will reset the AC4424. Do not
power up the transceiver with this pin tied Low.
16 GND
GND Signal
Ground
17 I Command/Dat
a
When logic Low, transceiver interprets Host data as command data. When logic High,
transceiver interprets Host data as transmit data.
transceiver interprets Host data as transmit data.
18
NC No
Connect