How can DCS and SIS clocks be synchronized more reasonably
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In chemical plants, it is important for DCS and SIS to be clock-synchronized, especially for critical interlocks. If the clocks are not synchronized, it can pose a serious risk to the device. Some manufacturers use triggers to send signals to both systems simultaneously in order to enforce synchronization, but the frequency of these signals is an issue. Some use GPS, but the cost is relatively high. Every supplier claims that their own option is the most reasonable. I’m not sure how people handle this issue in engineering projects; I would appreciate any advice you can offer!
Our company uses DCS to send a synchronization signal to the SIS at 2 a.m. every night in order to achieve synchronization. It seems to work fine, and no problems have occurred. Additionally, SIS and DCS handle different situations; if properly designed, they should not pose any major risks.
That’s a great question! The method mentioned above can be used, but the interval between the synchronized pulses can be made smaller. SIS and DCS are two completely independent systems, but the signals from SIS can be displayed and recorded on the DCS through communication. The importance of time synchronization between DCS and SIS lies in the analysis of the initial cause after a SIS action is triggered.
Personally, I think issuing a safety level update once a day is too infrequent; for devices that are extremely dangerous, even just a few hundredths of a second can have serious consequences.