Chengdu Ebyte Electronic Technology Co,;Ltd
E90-DTU (900SL22-GPRS) user manual
Copyright ©2012–2019，Chengdu Ebyte Electronic Technology Co,;Ltd
16
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4
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The radio frequency terminal has the function of Listen before talk (LBT), which enables the radio
station to actively Listen to the environmental noise of the channel after sending data to the server. If the noise
exceeds the threshold, the transmission will be delayed. This function can greatly improve the success rate of
radio communication with radio frequency in harsh environment. This function can be used for network
transmission and conflict prevention.
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5
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Fixed point transmission: support address function, radio frequency terminal can transmit data to
other wireless devices at any address and any channel to achieve networking, relay and other applications: for
example, the radio needs to transmit data to E22 cofrequency series module B (address 0x00 01, channel 0x80),
and its communication format is: 0001 80 AA BB CC, where 0001 is the address of module B and 80 is the
channel of module B, then module B can receive AA BB CC, and other modules do not receive data (the same
is true for E90-DTU (xxx-SLXX) series stations).
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6
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LoRa spread spectrum: LoRa direct sequence spread spectrum technology will bring more
communication distance; Low transmission power density, not easy to cause interference to other equipment;
9
、
Factory recovery
There are two ways to restore the factory
：
Software restore factory: users can configure software through the E90-DTU (900SL22-GPRS) officially
provided. In the configuration mode of GPRS/2G network transmission and RF configuration mode, click
the "restore from factory" button to reset the GPRS/2G module and RF module. Note: if the "restore
factory" button is clicked in the configuration mode of GPRS/2G network pass-through, after all
parameter modification operations are completed, the "module restart" button should be clicked again to
enable the restored factory or configured GPRS/2G network pass-through parameters to take effect.
Hardware restore factory
：
The user can press the Reload button on the side of the radio station for 4~10S
and all parameters will be restored to the factory setting. At this time, the system will automatically
switch to the communication mode.
Summary of Contents for E90-DTU 900SL22-GPRS
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