S7-200 converts an analog value (such as temperature or voltage) into a word-length (16-bit) digital value.
You can use the area identifier (AI), the data length (W) and the starting byte address to access these values.
Since analog inputs of a word, and the even-number bytes (such as 0,2,4) started, it must be an even number byte addresses (such as AIW0, AIW2, AIW4) to access these values. Analog input value is read-only data, the actual accuracy analog conversion is 12.
Format: AQW [starting byte address] AIW4