u-blox ANTARIS 4, Руководство по системной интеграции

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Possible Asynchronous Serial Interface Configurations Data bit Parity bit Stop bit
Baud rate
9’600
19’200
38’400
8 N 1 4’800
57’600
115’200
Table 22: USART configuration
Th baud rates can be set individually for each Serial Port. Different
pr tocols on the same port are not supported.
e baud rates for RX and TX or for different
o
norm 1 Stop bit, usually short named ‘ 8N1 ’)
gle by
A al data transmission (with a configuration of 8 Data bits, No Parity,
of a sin te looks as follows:
D0 D1 D2 D3 D4 D5 D6 D7
Start of 1-Byte
(Always 0)
transfer
Start Bit
Possible Start of
(Always 1)
next transfer
Stop Bit
t
bit
= 1/(Baudrate)
al Transfer, 8N1
4.4.1.1 Error Conditions on USART Ports
such as NMEA or UBX, it does not make sense to change the default values of
rd Length or Bit Order, since these properties are defined by the protocol, not by the electrical interface.
t messages may be discarded
ill be transmitted completely
t be transmitted in the next sequence.
4.4.
e ort to use an autobauding mechanism. This mechanism gets active if
e
If multiple break conditions are encountered, the baud rate of the serial port is reduced to the next lower
standard baud rate
•
If the receiver detects multiple framing errors, the baud rate is increased to the next higher standard baud
rate.
!
Warning Don’t use the u-center AE autobauding feature if the GPS receiver autobauding is enabled.
!
Warning Some serial port cards/adapters frequently generate errors. The u-center autobauding may not work
reliably in this case. If you experience frequent errors, please set the baud rate manually.
Norm
Figure 67: Definition USART data packets
Please note that for protocols
Wo
No e If the baud rate is insufficient to transmit all enabled messages, some
and not transmitted. The receiver does not check whether a message w
in the remaining time. Discarded messages won’
1.2 Autobauding
Th user can individually configure each p
th receiver indicates an error when receiving data.
•
GPS Modules - System Integration Manual (SIM) (incl. Reference Design) Receiver Description
GPS.G4-MS4-05007-A1 Page 80