Chengdu Ebyte Electronic Technology Co.,Ltd.
【
2DI+2AI+2DO
】
MA02-AACX2220 User Manual
Copyright ©2012–2021
，
Chengdu Ebyte Electronic Technology Co.,Ltd.
14
4 Detailed function
4.1 Analog input AI
4.1.1 Analog input AI collection
The analog input AI measures the current signal, with acquisition range 0-20mA or 4-20mA, accuracy 3
‰
, and
resolution 12 bits. Adopt single-ended input, sampling frequency 10Hz, input impedance 100
Ω
.
4.1.2 Analog input AI filter parameters
The filter parameters of the AI channel can be set, the effective value is 1-16, and the default is 6.
Note:
(1) AI channel filter parameter is shared by all AI channels. The larger the filter parameter, the stronger the
anti-interference ability of AI sampling, while it has time delay at the same time .
(2) AI channel filter parameter address is 0x04B0, and the register type is holding register. Function code 0x06,
0x10. When writing AI filter parameters, if the written parameter value is not within the range of 1-16, it will
automatically take the closest value to write. For example, if writing filter parameter 0, the device will take 1 as the filter
parameter, and Modbus will not return wrong instruction in this case.
4.1.3 Analog input AI sampling range
Set the sampling range of all AI channels, valid values are 1 and 0 (default 0).
0
：
Represent 0
～
20mA
1
：
Represent 4
～
20mA
(1) The AI sampling range is shared by all channels. When the AI channel sampling range is configured as 4-20mA
sampling, if the current signal is lower than 4mA, the engineering value of the channel is converted to 0. For signals
greater than 20mA, there is no conversion limit, but it cannot exceed 25mA (there is a risk of equipment damage if it
exceeds 25mA).
(2) AI channel sampling range parameter address is 0x04B2, the register type is holding register, function code 0x06,
0x10. When writing the AI channel sampling range parameter, if the value of the parameter written is not within the
range of 0 to 1, it will automatically take the closest value to write. If the write sampling range parameter is 2, the device
will take 1 as the sampling range parameter. And MDOBUS does not return an error command.
