Modbus protocol register

ModBus There are four kinds of data ,DI、DO、AI、AO

DI: Digital input , Discrete input , One address, one data bit , The user can only read its state , Do not modify . For example, the buttons on the panel 、 Switch status , Fault state of the motor .

DO: Digital output , Coil output , One address, one data bit , The user can set the location 、 Reset , You can read back the status , Such as relay output , Start stop control signal of motor .

AI: Analog input , Input register , An address 16 Bit data , Users can only read , Do not modify , For example, the reading of a voltage value .

AO: Analog output , Holding register , An address 16 Bit data , Users can write , It can also be read back , For example, the current value of a control frequency converter .

Whatever these things are called , Its content is nothing more than these , The input signal can only be viewed by the user and cannot be changed , The output signal is controlled by the user , And can be read back . Discrete data has only one bit , The simulated data are 16 position .