Problem with the connection cable between DCS cabinet and computer
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A recent project required that the cabinets be placed in a new cabinet room, while the operating computer was placed in the existing central control room more than 800 meters away. I just want to ask: What is the communication cable connecting the cabinet and computer? How many do you want? thank you all * * .
This depends on the communication medium between your existing DCS cabinet and the host computer. Of course, since they are so far apart, it is recommended that you use fiber optic communication in the middle. If it is Ethernet, use Ethernet to fiber optic terminals on both sides, and use fiber optics to connect between them.
For such a long distance, priority should be given to optical fiber communication. The amount required depends on the number of computers to be connected. The communication must be redundant and leave a margin for backup. Single-mode optical cables are now generally used. It is best to take two paths in one place per day, but it is really not possible to walk on two bridges.
What the previous few said is very correct. In addition, if it is a small system with only a few dozen points or something that is not too important, SCADA or PLC can use 485. The transmission at this distance is no problem, but if you use a network cable, the distance of 100+ will not affect it (personal test). For longer distances, you need to switch to optical fiber.
What the previous few said is very correct. In addition, if it is a small system with only a few dozen points or something that is not too important, SCADA or PLC can use 485. The transmission at this distance is no problem, but if you use a network cable, the distance of 100+ will not affect it (personal test). For longer distances, you need to switch to optical fiber.
Use optical fiber, network cable can't transmit such a long distance. It is best to have two, each with more than two cores, and A/B network redundancy to prevent one fiber from failing.
Pay attention to signal attenuation during long-distance transmission, especially interference from strong electricity.
For DCS, this section is usually a network cable. According to our unit's actual solution, we use optical fiber transceiver + optical fiber. We use single-mode optical fiber to gather the three originally scattered main control rooms into one main control room, and the cabinets are not moved. Now there are four sets of equipment in one main control room, and the effect is quite good. I'll give you some suggestions. First, don’t use one optical fiber. It is recommended to use two multi-cores and lay them in separate paths. Each fiber must have spare cores. This is safer. In case the optical fiber is broken, two can ensure that there will be no control problems. Second, if the fiber optic transceiver is used properly, it must be of good quality. Third, the transceivers on both sides of each optical fiber use the same power supply. The two-channel optical fiber transceiver should preferably ensure one mains power supply and half UPS supply, which must be unified. For example, if there are two optical fiber paths a and b, then all the optical fiber transceivers on both sides of path a are powered by mains power, and the optical fiber transceivers on both sides of path b are powered by UPS. Fourth, if the switch has an optical port, it is recommended to connect it directly to the switch. Or switch to a switch with an optical port, which is easier.