Chengdu ebyte electronic Technology Co.,Ltd.
E840-TTL-GPRS03 User Manual
Copyright ©2012–2017
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Chengdu ebyte electronic Technology Co.,Ltd.
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2.2.1 Operating modes are as follows
：
1, The operating mode is divided into: transparent transmission mode, AT configuration mode
a) Transparent transmission mode: After power-on, the module works in the transparent transmission mode by
default, and automatically starts the network connection. When the connection is established with the server, any
data received by the serial port will be transparently transmitted to the server. At the same time, it can also
receive the data from the server. After receiving the server data, the module will output directly through the serial
port. The maximum length of data supported by this module is 512 bytes.
b) This module supports one-way Socket connection. The user can configured it as TCP Client or UDP Client. In
transparent transmission mode, the received serial port data will be directly transmitted to the network server, and
the received network server data will be directly output through the serial port.
c) AT mode: In this mode, the serial port data is regarded as an AT command.
d) Mode switching, after the serial port receives the “+++” frame data in the transparent transmission mode, the
RX pin receives any AT command within 3 seconds, and the mode switches to the AT mode. In AT mode, send
AT+EXAT<CR><LF> to switch to transparent transmission mode.
3. Network Function
a)
Short connection: In TCP Client mode, the short connection function is enabled. If there is no data reception
in the serial port or network port within the set time, the network connection will be automatically disconnected.
The short connection function is turned off by default. The connection time can be set from 2 to 255 seconds.
When set to 0, the short connection function is disabled.
b) Registration package: The registration package is closed by default. 4 options include: physical address when
connecting, send custom data when connecting, add physical address before each packet of data, add
custom data before each packet of data. The maximum data length for customize registration package is 40
bytes (when set to HEX format, the maximum length is 20 bytes)
c) Heartbeat packet: In the idle state of network communication, the heartbeat packet is used for network state
maintenance. The heartbeat period can be set from 0 to 65535 seconds, and the maximum length of the
heartbeat packet is 40 bytes (when set to HEX format, the maximum length is 20 bytes). Supports two types
of heartbeats, network heartbeat, serial heartbeat. User selects network heartbeat, starts timing when in
communication idle, and sends heartbeat packets to the server according to the configured heartbeat period.
User selects the serial port heartbeat, start timing when in communication idle, and send heartbeat packets to
the serial port according to the configured heartbeat period.
Clear the cache: Before the connection to the server is established, the data received by the serial port will
be cached. When the connection with the server is established, you can choose whether to clear the cached
data. By default, the cache is cleared.
The maximum packet length of the local cache is 256 bytes.
