AeroComm AC4424, User Manual

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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
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.
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.
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.
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:
*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.
13 O RSSI Received Signal Strength Indicator - An analog output giving a relative indication of
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.
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.
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.
18 NC No Connect