Quectel BC68 Hardware Design

GSM/GPRS Module Series
M66 Hardware Design
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If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise
the URC will be discarded.
Restrictions on autobauding operation:
 The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).
 The “At” and “aT” commands cannot be used.
 Only the strings “AT” or “at” can be detected (neither “At” nor “aT”).
 The Unsolicited Result Codes like RDY, +CFUN: 1 and +CPIN: READY will not be indicated when
the module is turned on with autobauding enabled and not be synchronized.
 Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects
the new baud rate by receiving the first “AT” or “at” string. The DTE may receive unknown characters
after switching to new baud rate.
 It is not recommended to switch to autobauding from a fixed baud rate.
 If autobauding is active it is not recommended to switch to multiplex mode.
To assure reliable communication and avoid any problems caused by undetermined baud rate between
DCE and DTE, it is strongly recommended to configure a fixed baud rate and save it instead of using
autobauding after start-up. For more details, please refer to the Section AT+IPR in document [1].
3.7.1.2. The Connection of UART
The connection between module and host using UART Port is very flexible. Three connection styles are
illustrated as below.
Reference design for Full-Function UART connection is shown as below when it is applied in
modulation-demodulation.
TXD
RXD
RTS
CTS
DTR
DCD
RI
TXD
RXD
RTS
CTS
DTR
DCD
RING
Module (DCE)
Serial portUART port
GND GND
PC (DTE)
Figure 14: Reference Design for Full-Function UART
NOTE
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Quectel BC68 Specifications

General

Brand	Quectel
Model	BC68
Category	Control Unit
Language	English