Telit Wireless Solutions HE910 - MODEM SERIAL PORT 1 (USIF0) Details

HE910 Hardware User Guide
1VV0300925 Rev. 32 Page 78 of 111 2019-11-25
MODEM SERIAL PORT 1 (USIF0)
The serial port 1 on the HE910 is a +1.8V UART with all the 7 RS232 signals.
It differs from the PC-RS232 in the signal polarity (RS232 is reversed) and levels.
RS232
Pin #
Signal
HE910
Pad Number
Name
Usage
1
C109/DCD
N14
Data Carrier Detect
Output from the
HE910 that indicates
the carrier presence
2
C104/RXD
M15
Transmit line *see
Note
Output transmit line
of HE910 UART
3
C103/TXD
N15
Receive line *see
Note
Input receive of the
HE910 UART
4
C108/DTR
M14
Data Terminal
Ready
Input to the HE910
that controls the DTE
READY condition
5
GND
M12, B13,
P13, E14 …
Ground
Ground
6
C107/DSR
P14
Data Set Ready
Output from the
HE910 that indicates
the module is ready
7
C106/CTS
P15
Clear to Send
Output from the
HE910 that controls
the Hardware flow
control
8
C105/RTS
L14
Request to Send
Input to the HE910
that controls the
Hardware flow
control
9
C125/RING
R14
Ring Indicator
Output from the
HE910 that indicates
the incoming call
condition