Analog-to-Digital (AD) Conversion Method
The IO-SA0400Y and IO-SA0800Y analog modules use input analog-to-digital conversion.
Sampling Processing
Sampling processing converts analog input signals to digital signals through general analog-to-digital conversion processing. The digital conversion value is saved to the buffer memory of the each module.
The required time for sampling processing is a 2.1ms interval. This is regardless of the number of channels used.
Average Processing
Average processing is used to execute analog-to-digital conversion of the channel designated for average amount or average times. The average of the accumulated sum is saved in the buffer memory of the IO-SA0400Y and IO-SA0800Y.
If the setting value of the average time is specified, it does not read the analog-to-digital conversion value, but it receives the analog-to-digital conversion value gained by the time interval. The received value is used for the average count process.
The decimal point of the analog-to-digital conversion is ignored.
The setting range of the average count process is 1 ~ 255 (times).
The setting range of the average time process is 0 ~ 255 (×10)ms.
If the setting value of the average time processing is 0, only the average count processing is executed.
If the average count process is set to 10 times, the module receives sampling data every 2.1ms (10 times) and executes average processing. The average value of the input signal during 2.1ms is then output as the analog-to-digital conversion value. In this case, the interval time is 2.1ms.
If the average count process is 10 times and the average time process is set to 5 (50ms), the sampling data is taken every 50ms. It executes average processing with the sampled values received 10 times. As a result, the average input signal value over 500ms will be output as the analog-to-digital conversion value. In this case, the interval time is 50ms.
Digital Output Value Setting
When the digital output value is saved to buffer memory, the signed value 14-bit data (-8,000 ~ 8,000) or unsigned value 14-bit data (0 ~ 16,000) can be selected.
Please refer to the specific module’s buffer memory.
Precise Value
The precise value indicates the digital output value in relation to the analog input signal for each channel. This allows users to view precise values without additional data processing.
Current
| Analog Input | Precise Value |
|---|---|
| 0mA ~ 20mA | 0 ~ 20,000 |
| 4mA ~ 20mA | 0 ~ 5,000 |
Voltage
| Analog Input | Precise Value |
|---|---|
| 0V ~ +5V | 0 ~ 5,000 |
| +1V ~ +5V | 1,000 ~ 5,000 |
| -10V ~ +10V | -10,000 ~ 10,000 |
| 0V ~ +10V | 0 ~ 10,000 |
Percentile Value
The analog-to-digital conversion value (0 ~ 10,000) for each channel indicates the percentage compared with the input signal range.