I would like to ask how to control an electric valve that is 1150 meters away?
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There is an electric valve on a pipeline in the project, located 1150 meters away from the control room; the PLC is situated in the control room. Is it possible to use Profi-Bus for control? Is there any way to use fiber optics for control as well? Thank you
Intelligentization, using fieldbuses such as Profibus.
If there is no need to pursue advanced features, using 4-20mA current signals and copper wires would suffice; this is likely to result in the lowest investment.
For the wireless remote transmission system, we’ve found it to be quite useful; the range is currently around 3 kilometers
The wireless transmission mentioned above might be good, but for the electric valve described by the original poster, I still recommend a direct cable connection.
I think it’s better to control electric valves directly with cables; they can also be controlled using Profi-Bus or fiber optics. Primarily, the control system using the rear profi-bus or fiber optic electric valves requires interfaces; additional investment is needed, and attention must also be paid to electromagnetic interference issues.
4-20ma is more than sufficient to meet the basic requirements; I’m not sure what more advanced features the client is looking for If you have the money to be extravagant, you can implement anything you can imagine – bus fibers, wireless technology, and so on – but is it really necessary?
It’s sufficient to use analog signals for control; using PROBUS adds cost.
1150 meters of copper cable, using Profi-Bus; theoretically, it’s around 1200 meters without any repeaters
Using 4-20mA and digital signals directly – the voltage drop and resistance over 1150 meters seems a bit confusing
An electric control valve; the 2*2.5 mm² shielded flexible cable is perfectly fine. I think 2*1.5 is also fine. For specific calculations, refer to this: Calculation of the Maximum Installation Length and Selection of Cross-Section for Instrument Signal Cables, by Fan Wenjin (Yangzi Petrochemical Design Company, Nanjing, Jiangsu Province, 210048). There is another standard that can also be used as a reference. This is the cheapest and most economical method; other options will definitely cost more than this.