CC864-DUAL Hardware User Guide
1vv0300791 Rev 4.4 – 2011-01-26
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights Reserved.
Page 36 of 63
RS232
Pin
No
Signal
Pin No
Name
Usage
Detect
that indicates the carrier
presence
2
C104/RXD
26
Transmit line
Output transmit line of CC864-
DUAL UART
3
C103/TXD
25
Receive line
Input receive of the CC864-
DUAL UART
4
C108/DTR
29
Data Terminal
Ready
Input to the CC864-DUAL
controlling the DTE READY
condition
5
GND
5,6,7
Ground
Ground
6
C107/DSR
27
Data Set Ready
Output from the CC864-DUAL
indicating the module is ready
7
C105/RTS
31
Request to Send
Input to the CC864-DUAL
controlling the hardware flow
8
C106/CTS
28
Clear to Send
Output from the CC864-DUAL
controlling the hardware flow
9
C125/RIN
G
30
Ring Indicator
Output from the CC864-DUAL
indicating the incoming call
condition
NOTE:
According to V.24, the RXD and TXD signals are referred to from the
perspective of the application. Therefore, these signals are referred to in the opposite
direction for the module: TXD on the application side will be connected to the receive
line (here named
TXD
/Receive line) of the module’s serial port and vice versa for
RXD.
TIP:
For a minimum implementation, only the TXD and RXD lines need to be
connected, leaving the other lines open, provided software flow control is
implemented.
3.8.1.1.
Diagnostic Monitor Port
The CC864-DUAL has a diagnostic monitor port:
Diagnostic Monitor
23
RX_TRACE
I
RX Data for debug monitor
24
TX_TRACE
O
TX Data for debug monitor
TIP:
Make this port available on test pads or internal headers in order to facilitate
capturing test and debug data from the module. If not, the module USB port should
be accessible on the module as this port can perform the same function!