In addition to bus isolation, independent isolation uses a photocoupler and an isolation amplifier to add isolation between each input/output channel. Independent (channel-to-channel) isolation Bus isolation (Analog I/O Multi-function DAQ).Because it's possible to prevent electrical interference from being introduced, this method allows for worry-free usability even if noise is easily generated in the wiring or if there is a concern of the computer malfunctioning or becoming damaged. Using a photocoupler, the computer and external I/O circuits are isolated. Note that non-isolated types do not employ an isolation element. Let's look at the features of two types of isolation. This is the basic idea behind quantizing analog quantities.Īnalog I/O devices can be broadly classified into two categories: isolated and non-isolated. In this way, an analog quantity can be digitalized at 4 bits. Cell phones make calls by converting voices (analog) to digital sounds.įor example, the following figure shows a staircase in decimal numbers with the first step as 1, as well as the result if the decimal numbers are replaced with binary numbers. This technology is active in things many people are familiar with, for example, in cellular phones. This makes it possible to express any analog signal using a finite value. When quantizing analog values represented by a solid line, you get a stepped line. In other words, this means replacing an amount within a certain range with a representative value. The most effective way to solve this problem is to keep the number of digits within the acceptable range by rounding or using either the floor or the ceiling. This is not possible with a computer capable of handling only a limited number of digits, even from the viewpoint of the circuit technology that makes up the converter. When inputting an external analog quantity into a computer, in order to display the quantity properly digitally, an infinite number of digits is need for the corresponding digital quantity. Analog I/O device(A/D, D/A conversion)Īnalog I/O devices are devices with both an A/D conversion function and a D/A conversion function. This device converts the digital data from a computer to an analog signal before outputting that signal to an external device. This device is responsible for converting analog signals from external devices to digital signals that can be processed by a computer. (Digital Multimeter Board,Digitizer Board)Īnalog I/O device classification Analog input device(A/D conversion) That bridge is called an analog I/O interface. For this reason, in order to input a signal from a sensor using a computer, or to output a signal to an actuator, it's necessary to have a device that can bridge the analog signal and the digital signal handled by the computer. On the other hand, only digital signals can be handled by computers. The signals from sensors that measure surrounding natural factors such as temperature, pressure, and flow rate are often analog signals, and most control actuators move according to analog signals. Types of noise and applicable countermeasures.Expressing analog values as digital values.Relationship between binary and voltage.Recommended sampling rate: 10 times the frequency being measured.It may also prove a useful resource for individuals already using CONTEC analog I/O devices. The content offered here is recommended knowledge for anyone looking to perform measurement control using a computer as well as anyone considering automating data logging or measurements. This section offers basic knowledge and glossary terms related to analog I/O, A/D conversion, and D/A conversion in an easy-to-understand way that includes illustrations.

16 bit resolution calculator