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Chengdu Ebyte Electronic Technology Co.,Ltd.
ME31-AAAX2240_UserManul_EN
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2.2 Device connection
2.2.1 RS485 connection
Note: When the 485 bus high frequency signal is transmitted, the signal wavelength is shorter than the transmission
line, and the signal will form a reflected wave at the end of the transmission line, which will interfere with the
original signal. Therefore, a terminal resistance must be added at the end of the transmission line to prevent the
signal from being reflected after reaching the end of the transmission line. The terminal resistance should be the
same as the impedance of the communication cable, with a typical value of 120 ohms. Its function is to match the
bus impedance and improve the anti-interference and reliability of data communication.
2.2.2 AI analog input connection