Can the data transmission of sensors and instrument control components at the site be achieved wirelessly?
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In an automated factory, the data cables connecting various devices and instruments are as numerous as a spider’s web. To transmit data from a small temperature or pressure sensor to the control center, it is sometimes necessary to use cables that span long distances; as a result, it’s common to hear that for each project or installation, the total length of the cables used is equivalent to the distance from the Moon to Earth. If all these sensors could achieve wireless transmission, it would save so much material and reduce the amount of work required. I wonder if there is any research in this area currently?
Wireless transmitters do exist, but when using wireless technology, the cost of cables is saved; however, the cost of the transmitters increases, as does the cost of debugging, along with maintenance costs and so on. I’ll need to replace the battery in the transmitter again in a while
Yes, it’s relatively simple, but its stability is uncertain; also, it’s likely vulnerable to lightning strikes.
Yes, wireless is generally used for monitoring data rather than for control purposes. It can certainly be used for control as well, but the standards and requirements become higher, which naturally leads to an increase in price
Yes, many brands offer transmitters with wireless transmission. However, it has relatively strict requirements for the application environment: low electromagnetic interference, and the signal transmission path should have no walls to penetrate or few obstacles. Additionally, if the signal is used for control purposes, it must comply with various specifications; for instance, some industries require the use of cable wiring.
It is widely used in oil fields, and Emerson has also been promoting it in recent years. Overall, it has both advantages and disadvantages!
Would you dare to use wireless? How is battery power supported? What can be done to avoid signal interference once it occurs? Encountering thunderstorms during use is also a major problem. Moreover, since everything is wireless, the price will definitely be very high; I’m afraid that once you see it, you might find it cumbersome and unattractive… To avoid using cables, field buses can be used. I’ve seen sewage treatment plants use PROFIBUS for communication – there are few cables in such systems, and the cable trays are also of a relatively thin type. The control system relies on PLC configurations. However, chemical companies strive for stable production and simple maintenance; therefore, they opt for a setup using one sensor per cable. So... it’s better to stick to traditional methods – there’s nothing wrong with that. Once fieldbus technology becomes more advanced, we won’t need to purchase so many cables, and then those cable manufacturers will be able to close down……
Having the instruments upstairs is a good approach. It’s recommended to choose instruments that use a bus protocol, as they require less wiring and are easy to configure. The wireless module has too many serious flaws at the moment; it can be used in less critical applications
Isn’t Emerson promoting wireless technology these days? You can go and take a look. The price, oh my god. One of these is equivalent to ten domestic wired ones. . . But according to them, the quality is truly good.
The decentralization of PLCs or DCSes, by concentrating the instruments of a single device or part of a device in one controller or remote I/O unit and then transmitting the signals using wireless technology, seems to be a practical approach at present.
I also think it is feasible to consolidate some of the instruments in one I/O cabinet and then send the signals from that cabinet out collectively; in this way, each I/O cabinet can function as a wireless transceiver station, allowing for increased wireless power and greater stability in wireless transmission.