User's Manual

GE864
GE864GE864
GE864-
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-QUAD V2 / GE864
QUAD V2 / GE864QUAD V2 / GE864
QUAD V2 / GE864-
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-DUAL V2 Hardware User Guide
DUAL V2 Hardware User GuideDUAL V2 Hardware User Guide
DUAL V2 Hardware User Guide
1vv0300875 Rev.1 – 2010-03-29
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved. Page 37 of 73
9. Serial Ports
The serial port on the Telit GE864-QUAD V2 / GE864-DUAL V2 is the core of the
interface between the module and OEM hardware.
2 serial ports are available on the module:
• MODEM SERIAL PORT
• MODEM SERIAL PORT 2 (TRACE for debug)
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 GE864-QUAD V2 / GE864-DUAL V2 is 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 / GE864-DUAL V2 UART are
the CMOS levels:
Absolute Maximum Ratings
Absolute Maximum Ratings Absolute Maximum Ratings
Absolute Maximum Ratings –Not Functional
Not FunctionalNot Functional
Not Functional
Parameter
ParameterParameter
Parameter Min
MinMin
Min Max
MaxMax
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