Notes - Ebyte E840-TTL-4G02E User Manual

Chengdu Ebyte Electronic Technology Co.,Ltd.

5 Notes

The first Socket of this module will always be opened. After the initialization is successful, it will

automatically establish a connection with the configured network server.
After the module is powered on, it cannot be initialized successfully. That is, the State indicator has no

indication for more than 30 seconds. In this case, check whether the module is installed properly, whether the
SIM card is properly inserted, and whether the SIM has failed.
Short connection function can be used to reduce the connection pressure of multiple devices to the server.

When the short connection function is enabled (AT+SHORTM>2), the module will actively disconnect the
connection when the network or serial port has no data for more than the short connection setting period.
After the disconnection, the network cannot send data and the local serial port sends. For valid data, the
module will immediately establish a connection with the server. If the local clear cache function is turned off,
the packet will be cached (maximum 10K bytes). After the connection is successful, the data will be sent to the
server. The local cache function is cleared and the packet will be discarded.
The heartbeat function is used to maintain the connection after the module and the server are successfully

connected. In the network, if the client and the network server successfully establish a connection and there is
no data transmission for a long time, the Socket link may appear "dead" , that is, the chain. The road exists but
cannot send and receive data. Therefore, in actual use, it is recommended to enable the heartbeat packet
function to ensure the reliability of the network link.
In actual use, it is normal for the data delay of the two communications to be different.

After the protocol is closed, the maximum single packet length supported by a single link is 10K bytes. A local

serial port or a network sending a packet exceeding this length may cause packet abnormality. The distribution
protocol is enabled. Each Socket is enabled. The link single packet can support up to 1024 bytes
(user-configured serial port packing length).
In the high-speed serial transmission mode, the EMBMAC and EMBCSTM registration package functions

Copyright ©2012–2022，Chengdu Ebyte Electronic Technology Co.,Ltd.
E840-TTL-4G02E User Manual
17