I suddenly thought of a question: what is the difference between DCS and SIS? I hope experts can answer it!
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I suddenly thought of a question: what is the difference between DCS and SIS? I hope experts can answer it! We talk about this being DCS and that being SIS all day long; this goes into DCS and that goes into SIS. So what is the fundamental difference between DCS and SIS? I hope someone knowledgeable can answer this! ! !
This is a serious issue. DCS is a dynamic control system that can also be used for emergency shutdowns, but its response time is too long; in contrast, SIS offers a more rapid and sensitive response, in my opinion
Thank you for your participation. I remember having this question in an exam before; back then I just wrote down a few random answers. Now I’ve remembered it again, and I hope everyone can help to answer it!
http://bbs.hcbbs.com/thread-1633101-1-1.html
DCS Distributed Control System, SIS Safety Instrumented System
Why can control loops sometimes be implemented in SIS, and can pump start/stop operations be handled in DCS as well?
Personal understanding: DCS is a control system that enables conventional control. SIS is a safety instrumented system, equivalent to an ESD system, for control in emergency situations.
DCS is a system that provides centralized control over distributed detection units and regulates production parameters. In terms of signal types, there are AI, DI, AO, and DO. SIS is an emergency shutdown system that serves as a protection mechanism; it comes into action when serious accidents occur in the facility or when the monitoring data for key equipment exceeds specified limits. The signal types include AI, DI, and DO
The ESD system is a type of SIS system
DCS and SIS have a similar structure; the only difference lies in the reliability requirements for hardware and software, as well as in their configurations. Generally, signals or control loops that do not affect equipment and production safety are fed into the DCS, while signals or interlock operations that affect equipment and production safety are fed into the SIS. SIS is a backup protection mechanism for DCS. My personal understanding; for reference only
You can take a look at the connection in #4; this will help you understand better. SIS offers a higher level of safety for control circuits, and it is used in applications where high safety standards or a high degree of risk are required. In case of an emergency, it enables timely safety responses, such as the immediate shutdown of valves. On the other hand, DCS does not provide such a high level of safety; it is mainly used for automated production and falls under process control.