User's Manual

GE/GC864-QUAD V2 and GE864-GPS Hardware User Guide
1vv0300915 Rev.2 – 2011-06-15
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights
Reserved. Page 58 of 97
9. Serial Ports
The serial port on the Telit GE864/GC864-QUAD V2 and GE864-GPS
is the core of the interface between the module and OEM
hardware.
2 serial ports are available on the GE864-QUAD/GC864-QUAD V2
modules:
• MODEM SERIAL PORT (Main, ASC0)
• MODEM SERIAL PORT 2 (Auxiliary, ASC1)
While another serial port is available on the GE864-QUAD
V2/GPS module:
• GPS SERIAL PORT (NMEA)
9.1. MODEM SERIAL PORT
Several configurations can be designed for the serial port on
the OEM hardware, but the most common are:
• RS232 PC com port
• microcontroller UART @ 2.8V – 3V (Universal
Asynchronous Receive Transmit)
• microcontroller UART@ 5V or other voltages different
from 2.8V
Depending from the type of serial port on the OEM hardware a
level translator circuit may be needed to make the system
work. The only configuration that does not need a level
translation is the 2.8V UART.
The serial port on the GE/GC864-QUAD V2 and GE864-GPS a +2.8V
UART with all the 7 RS232 signals. It differs from the PC-
RS232 in the signal polarity (RS232 is reversed) and levels.
The levels for the GE864-QUAD V2 UART are the CMOS levels:
Absolute Maximum Ratings –Not Functional
Parameter
Min
Max
Input level on
any digital pad
when on
-0.3V +3.1V
Input voltage
on analog pads
when on
-0.3V +3.0 V