How is communication between DCS and SIS systems configured?

No one can answer what LZ is talking about – which manufacturer’s DCS and SIS they are, and how they are connected at the hardware level

It’s extremely vague; my answer is to set it in the DCS configuration.

Another beginner at the absolute novice level, hehe. It’s impossible to think of one solution and resolve all difficulties at once. Since the poster is looking for help, you should at least let everyone know which manufacturer’s DCS and SIS systems you are referring to, as well as their model numbers. If even this basic information isn’t provided, how can anyone help you? The communication protocols and links between DCS and SIS from different manufacturers vary.

The question posed by the original poster is too broad; please be more specific so that it’s easier for others to help.

Generally, communication between DCS and SIS systems from different manufacturers relies on Modbus. If they are products from the same manufacturer, there may be special connection methods; for example, the FSC and TPS systems use SMM cards, while the PKS systems use 10084 Ethernet cards. The communication protocols are usually not made public.

The MODBUS485 RTU protocol is usually used for communication; you can find out by asking the manufacturers of the two systems.

MODBUS RTU mode: Generally, a SIS does not require signals from a DCS; the safety level of a SIS is higher than that of a DCS. The common approach is to transfer the relevant data from the SIS to the DCS, with the DCS merely capable of reading this data to facilitate operator operations and provide insight into the process conditions. As for the specific method of communication, it depends on how the DCS and SIS manufacturers have configured MODBUS. For Yokogawa DCS systems and×××’s SIS (as known by the original poster), it is sufficient to correctly obtain the internal address of the SIS during communication (refer to ALR121 settings), and then configuration can be done on the DCS

It depends on the communication protocol between the DCS and SIS manufacturers.

Can it be considered that SIS is the same as ESD?

From a signal perspective, DCS is used for process control, and its input and output signals can be either analog or digital; whereas SIS systems are primarily used for interlock protection, so their signals are mainly digital on/off types. Put simply, SIS only needs to know whether cascading protection is triggered; it doesn’t care at all about how the process unfolds. Therefore, DCS and SIS don’t really require any communication protocols; if it’s necessary to obtain signals from the DCS, then simply use the DOs of the DCS to get the digital signals. Taking signals from a DCS is something that should be done only as a last resort. The SIS system is a device with high safety standards, and it should receive signals of equal high security level; by obtaining signals from a DCS device, the safety level of use is reduced. At least I haven’t done that. The approach I’ve encountered is that after the field signals are brought into the control room, they are connected to both the SIS and DCS at the terminal blocks. If the signal is analog, it can be passed to SIS by using a setter (1 for 1, 3 for 2, depending on your requirements regarding safety levels), and then the DO output from the setter is used. In this way, DCS and SIS operate independently of each other. Make sure not to end up with me in you and you in me. People who know the subject will laugh at you. :lol