Analog Inputs are very special in that they are sensitive to voltage changes. Analog to Digital (A/D) conversion is the process of converting a voltage in the range of 0 to 5VDC into a number that can be processed by custom software that you develop. The ProXR Command Set will allow you to send a command to the board and read voltage levels from 0-5 volts using 8-bit resolution. 8-Bit resolution will read the voltage input (from 0 to 5VDC) and then is interpreted as a value from 0 to 255. Zero being a contact closure input.
A voltage input of 0 Volts is interpreted as a value of 0
A voltage input of 2.5 Volts is interpreted as a value of 127
A voltage input of 5 Volts is interpreted as a value of 255
So if you divide 5 Volts by 255 possible steps (0-255 for 8-Bit resolution), the board is sensitive to voltage changes as small as 0.019 Volts. This controller has eight A/D inputs, each input is capable of reading a separate voltage from 0 to 5 VDC, provided all voltages can share a common ground. This is particularly useful for reading temperature sensors (one temperature sensor is built into select boards mostly 4 & 8 channel, shared with analog input number 8). A/D Inputs are also useful for reading light level sensors, thermocouples, switch closures, or just about any other kind of sensor you can think of.
A/D Sample Programs Available
Eight Different A/D Sample programs are available in the
Component Library. These samples are available as a free download and are compatible with Visual Studio.