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 41 of 73
The RS232 serial port lines are usually connected to a DB9 connector with the
following layout:
9.3. 5V UART Level Translation
If the OEM application uses a microcontroller with a serial port (UART) that works at
a voltage different from 2.8 – 3V, then a circuitry has to be provided to adapt the
different levels of the two set of signals. As for the RS232 translation there are a
multitude of single chip translators. For example a possible translator circuit for a 5V
TRANSMITTER/RECEIVER can be: