Beijing ART Tech A-GPRS1090I, User Manual

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Beijing ART Technology Development Co., Ltd.
Table
3.13
Support baud-rates
Standard baud-rate
300 600 1200 2400 4800 9600 19200 38400 57600 115200
SERDAT
，
SERSTP
These parameters control the format of the serial’s data and characters, users can change these parameters according to
requirements of their own devices.
SERCHK
This parameter controls the serial’s checking types at the time of communicating, the relationship between values and
checking types are shown in Table
3.15.
Table
3.15
relationship between values and checking types
Baud-rate No checking Odd checking Even checking
Compulsory
to 1
Compulsory
to 0
Set value
NON ODD EVEN
1 0
BEATTIM
Module has connected to the server, if did not produce data streams for a long time, this connection will be cut off by
operators. In order to maintain connections actively, the module will be intermittent to send one meaningless byte to the
server; this data is known as the heartbeat packet. The time between two heartbeat packets can be set according to the
local network, usually is tens of seconds.
Users can set heartbeat packet interval time through this parameter, it is from 30s to65, 534s.
BEATDATA
We can also set the heartbeat data by ourselves, such as: "0x3F", using the AT command to configure, format is: "AT +
BEATDAT = 3F".
SERS
，
MTU
If in the time of frame interval did not receive new data, the serial would receive a byte data. then the byte before serial
data is as a packet, the next byte of data is as the next packet starting. If users have requirements of data frame
transmission, you can use the sub-Ways.
In the GPRS network too large packets will increase the transmission delay, and easily lost data, so users would be
according to the local network to set up a reasonable maximum length packet. When receives data packet which reaches
the maximum, the module will sent them as a data packet, these movements for users is transparent (can be said to be
hidden also).
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