Regarding wiring issues
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Dear seniors: Hello, I would like to ask what is used to connect the instrument cable for long-distance signal transmission to the I/O card, and then from the I/O card to the DCS main unit? Use communication optical cables? What if the signal goes from DCS to ESD? Use a communication optical cable? Use an Ethernet cable? I’m a bit confused. I would appreciate it if those who are aware of this could share their insights. Thank you.
This post was last edited by budaoweng123 on 2016-6-14 at 13:56. What is used to connect the I/O cards to the DCS host? Generally, it is the manufacturer’s own pre-fabricated cables; of course, there are also those from companies like Emerson DeltaV and Honeywell that combine the connectors and terminals into one unit. If the distance is too great, DCS manufacturers offer solutions such as remote racks that use optical fibers. What if the signal goes from DCS to ESD? The vast majority are designed for a single cabinet, and ordinary control cables are sufficient.
I’m sorry, may I ask if a cable is still needed for the signal from DCS to ESD? Can I pull a communication cable? Or would an Ethernet cable work?
Between the I/O card and the DCS CPU, there is also a communication module (sometimes called a communication card). Communication between this module and the station controllers usually takes place via the RS485 protocol. In the case of PLCs, integrated processing is possible without the need for a communication module; however, communication modules are required when remote operation or expansion is needed.
It’s so complicated. Could you explain it in detail? Thank you!
The typical DCS wiring is as follows: field instruments — I/O cards — communication modules (one communication module for several I/Os) — (bus) controller CPU (sometimes referred to as a station) — (network cable) industrial computer