Difference between digital and analog quantities

The digital output can be either passive or active; in simple terms, it is sufficient to form a current circuit. There is no specific value for the current magnitude – the appropriate capacity is chosen based on the requirements of the load being driven. Digital signals are those that can be accepted by a DCS; they can be read by a computer without the need for signal conversion, and their voltage levels comply with the DCS specifications, similar to the 4–20 mA analog signal transmission method. It merely transmits voltage signals (which can be step signals, pulse signals, and so on). This post was last edited by backhamm1982 on 2008-1-3 09:59.]

The opposite of digital quantity is analog quantity. Digital signals include switch signals and pulse signals; physical quantities that are discrete in both time and magnitude are referred to as digital quantities. A signal that represents a numerical value is called a digital signal. For example, when using an electronic circuit to record the number of parts produced by an automated production line, a signal is sent to the electronic circuit each time a part is delivered, causing it to record a 1; whereas when no parts are delivered, a signal of 0 is sent to the electronic circuit, thus serving as the count. It can be seen that the signal representing the number of parts is discontinuous both in time and in quantity; therefore, it is a digital signal. The smallest unit of quantity is 1. Physical quantities that are continuous in terms of time or value are called analog quantities. A signal that represents an analog value is called an analog signal. For example, the voltage signal generated by a thermocouple during operation is an analog signal; since the temperature being measured cannot change suddenly under any circumstances, the voltage signal obtained is continuous both in terms of time and magnitude. Moreover, any value taken by this voltage signal during its continuous variation has a specific physical meaning, that is, it represents a corresponding temperature.

Agree with what was said on floor 3. The analysis is quite detailed

I always thought that digital signals and binary signals were the same thing; haha, it seems that digital signals are just a part of binary signals, haha

Digital signals are discrete, while analog signals are continuous.

How can a digital value be analog? Could you explain in detail!

The explanation on the third floor was very professional; it was repeated*.

Continuous learning is the only way to enrich oneself; thank you all

3rd floor: victory:

Thank you all, that was very clear:D

It should be the same thing, just different names.

Continuous learning is the only way to enrich oneself

The output signals are generally active, while the input signals are generally passive

I completely agree with the analysis on floor 3; it’s worth learning!*~

Generally, when we talk about digital switch signals, they are considered equivalent to digital signals. If we were to explore the difference: it might lie in the fact that digital signals originate from NC and NO. And the digital values come from levels 0 and 1, right? One is a physical contact, and the other is a high/low voltage signal (binary) for digital transmission.

That is, DI (digital input) and DO (digital output)