Chengdu Ebyte Electronic Technology Co.,Ltd.
E90-DTU(2G4HD12)
User Manual
Copyright ©2012–2020
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Chengdu Ebyte Electronic Technology Co.,Ltd.
14
6. Working Mode
6.1 Modes
Two working modes are controlled by M1 buttons.
Mode
Position
Description
Transparent
transceiving mode
0 (low level)
The serial port is open. DTU is in the state of receiving and sending,
transparent transmission (valid when LINK is low level)
Configuration Mode
1 (high level)
Users can query/set module parameters through the serial port, and DTU
stops sending and receiving.
Note: The transparent transmission mode will take effect only when the LINK-LED light is always on.
6.1.1 Transparent transceiving mode
When M1 is set to transparent transmission mode, data can be sent and received only when the LINK-LED is always on.
When the LINK-LED is off, it means that the module is searching for a device with the same communication link, and
communication is not possible at this time. After the device with the same communication link is searched and connected
successfully, the LINK-LED is always on. Communication.
6.1.2 Configuration Mode
In configuration mode, DTU cannot transmit or receive data via radio frequency. Users can send AT commands to DTU.
6.1.3 Mode Switching
The M1 button of DTU is used to switch the working mode. Mode will be switched in100ms after M1 button change.
6.1.4 DTU Reset
After DTU hardware reset or software restart, LINK-LED goes out, LINK-LED is always on after the connection is
completed, and starts to work normally according to the working mode specified by M1. Therefore, user data needs to be
transmitted wirelessly when the LINK-LED is always on.
6.2 DATA LED Indicator
DATA LED displays the state of transparent transmission, it indicates whether there is data receiving or sending on the
DTU communication interface, and it flashes when data is being sent or received.