Most PLCs/DCS, etc, control systems support several "standard" protocols, such as Fieldbus, Modbus, DeviceNet, etc.
Most manufactures now make "smart" instruments to take advantage of these protocols to make their devices more "compatible" with different systems.
TCP/IP is another recent trend to integrate with the plant "computer system" or "plant network" for the purpose of data transfer, storage, report generation, etc.
Have you talked to your PLC sales rep? They are a great source of where their company's products are going.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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