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9. Pin-out chart for ACC-513/514
9.1. Pin-out for ACC-513
Connector
No.
Pin
No.
Function Description
Input/
Output
1
VCC
6V to 12V Power Input
I/P
2 GND
Ground
3 PTT
Signal from the digital board to enable transmitter
circuit of modem board.
I/P
4
TXD_EN
It ensures that the radio has stabilized in transmission
before the data is processed for modulation.
I/P
5
TX_END
To finish transmission, it indicates memory buffer of
Master MCU of digital board is empty.
O/P
6 MUTE
(Busy)
Logic level input from digital board to indicate whether
a carrier is present or not
I/P
7
MODEM_EN
Modem Enable input
I/P
8
POWER_SAVE
Power save input for modem board.
I/P
9
CMD_EN
It indicates that command for Modem programming is
effective.
I/P
10
CMD_IN/OUT
Data Input and Output for Modem programming.
I/P,
O/P
11
CMD_CLK
Clock Input for Modem programming.
I/P
12 MODEM_SEL
It Indicates modem type to Master MCU for
programming.
O/P
13
RX_IN
The GMSK signal input for the receiver of modem IC.
I/P
Connector 1
14
TX_OUT
The GMSK filtered Tx output signal.
O/P
1
Serial_IN
The Serial data to be transmitted is input to this pin.
I/P
2
Serial_OUT
The recovered asynchronous serial data output from
the receiver.
O/P
3
Busy
To eliminate data loss according to buffer overrun of
slave MCU’s memory, it indicates buffer status.
O/P
4
Carrier_Detect
Handshake signal for RTS control mode. It indicates
whether Slave MCU of modem has decoded data or
not.
O/P
5
PTT_IN
Handshake signal for RTS control mode. It requests
data transmission to Slave MCU of modem.
I/P
Connector 2
6
PROGRAM
It’s reserved input for firmware upgrade.
I/P