GE865 Hardware User Guide
1vv0300799 Rev.9 – 27-07-2009
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 38 of 70
The signals of the GE865 serial port are:
RS232
Pin
Number
Signal
GE865
Pad
Number
Name
Usage
1
DCD - dcd_uart
B5
Data Carrier Detect
Output from the GE865 that indicates
the carrier presence
2
RXD -
tx_uart
A4
Transmit line *see Note Output transmit line of GE865 UART
3
TXD -
rx_uart
A3
Receive line *see Note
Input receive of the GE865 UART
4
DTR - dtr_uart
B3
Data Terminal Ready
Input to the GE865 that controls the
DTE READY condition
5
GND
C2, C7, E5,
E7, G1, G3,
G4, G5, H3,
H6
Ground
ground
6
DSR - dsr_uart
B2
Data Set Ready
Output from the GE865 that indicates
the module is ready
7
RTS -rts_uart
A1
Request to Send
Input to the GE865 that controls the
Hardware flow control
8
CTS - cts_uart
A2
Clear to Send
Output from the GE865 that controls
the Hardware flow control
9
RI - ri_uart
B4
Ring Indicator
Output from the GE865 that indicates
the incoming call condition
NOTE:
According to V.24, RX/TX signal names are referred to the application side, therefore
on the GE865 side these signal are on the opposite direction: TXD on the application
side will be connected to the receive line (here named TXD/ rx_uart ) of the GE865
serial port and viceversa for RX.
NOTE:
For a minimum implementation, only the TXD and RXD lines can be connected, the
other lines can be left open provided a software flow control is implemented.
