What do input and output points mean in DCS?

It’s really hard to answer this question.....

In general, a point is just a point; one point represents an input or output signal, and there is no such thing as any computation...

Different tables have different models, measure different quantities... and thus have different signal types. Any process value measured at the site is an input signal; anything that is sent as a control signal to the on-site controller is an output signal

Analog input point (AI): Continuous signals from the field or MCC, such as 4–20mA, RTD, TC, Hz, etc. Analog output point (AO): Continuous signals such as those from the field or MCC4–20mA. Digital input point (DI): Discrete signals from field or MCC active/passive contacts. Digital output point (DO): Discrete signals with (or without) active contacts at the site or in the MCC.

It’s difficult to answer this; generally, pressure needs to be calculated, and it’s quite complex in practice!

Counting the points is probably done to take into account the capacity of the DCS system and to configure the appropriate cards. First, one needs to look at the pipeline instrumentation diagram; this is the most fundamental thing. When counting the types and quantities of measuring instruments, it is necessary to communicate and learn from professionals in piping, process engineering, and equipment during this process. At the same time, it is also necessary to determine the communication signals with specialties such as electrical engineering.

This post was last edited by jors1983 on 2010-5-25 at 12:31. I think there is calculation involving a modulus conversion process. It is explained in the process how the analog signals coming from the field enter the IO cards and are converted into binary signals that can be recognized by the system. Once the analog signals reach the safety barrier, they are first filtered and processed; thereafter, the decimal signals are converted into binary computer signals based on the precision required by the cards, usually through hexadecimal calculations. But generally speaking, for engineering applications, it’s not necessary for us to carry out the calculations ourselves; we just need to understand the principles of signal conversion in order to comprehend the hardware of various systems. Original poster, are there any other specific issues that need to be resolved? Everyone can offer you some suggestions. Furthermore, input and output generally refer to the IO of hardware pins; please correct this.

Hehe, this has a lot to do with the regulations set by various manufacturers; it’s something they use to take advantage of users. But generally, it refers to hardware buttons that occupy dedicated hardware channels

The answer on the 5th floor is correct; it’s the standard answer. The 8th floor is nonsense.

In the field, input and output correspond to a transmitter that receives signals (such as control valves) or sends out signals (such as pressure transmitters). The situation is exactly the opposite for DCS cards: control valves correspond to analog output cards, while pressure transmitters correspond to analog input cards. In other words, one point represents one signal: the level of a substance corresponds to an analog signal, while temperature corresponds to an RTD signal. When a DCS counts signal points, it first classifies them based on input and output points, as well as fieldbus (two-way communication); this determines what type of main control card or controller will be used. Further down, these points are categorized into specific types such as AI, AO, DI, and DO