Relationships between control systems
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I don’t understand the relationship between these systems: what is the connection between DCS, SIS, CCS, Bentley 3500, and Haldex? I earnestly ask the expert to help sort this out.
I have only worked with DCS and 3500; the latter is a machine vibration monitoring device from Bentley. In fact, some simpler systems eliminate the need for 3500, with the vibration signals going directly to the DCS or PLC
What I can be certain of now is that the Bentley BN3500 shaft monitoring system operates within the architecture of the CCS unit control system.
Each system has its own unique functions, and strictly speaking they cannot be replaced, although some functions are repetitive
DCS is used for basic process control; SIS is primarily used for safety interlock protection; CCS is mainly used for unit control and protection. 3500 is used for monitoring signals such as vibration, displacement, and keyphasor of the unit. I haven’t come across Helbig before – it seems to be a unit manufacturer
Everyone, please note that what I want to know is the network architecture layout of these systems and the connections between them; there’s no need to explain what each one represents.
Let me talk about the relationship between DCS and 3500. Generally, the 3500 receives signals from sensors located on site, processes and analyzes them, and then outputs DO signals to the DCS in order to trigger shutdowns (based on interlocks related to vibration and displacement levels); the DCS also has its own interlock conditions related to temperature, oil pressure, and other parameters, which are used to control electrical circuits or other unit protection systems. As for the analog quantities such as vibration, displacement, and phase shift, they can be transmitted to the DCS for display and archiving in two ways: via 4-20mA signals or through communication (with Modbus RTU being the most common method)
In DCS, it is process control as well as sequence-related control, and similar controls are also present in SIS. Some people say that DCS can fully fulfill the control functions of SIS, so there is no need for SIS. But in reality, SIS is essential in large petrochemical plants
DCS, SIS, CCS, Bentley 3500, and Haldex are all independent control systems. DCS and SIS can communicate over a single control network, while CCS, Bentley 3500, and Haldex generally can only communicate with the DCS. Communication methods include MODBUS, Ethernet, etc. These are third-party control systems that can be integrated with the DCS human-machine interface.
DCS, SIS, and CCS are all independent control systems. The Bentley 3500 is generally used only for signal conversion of shafting instruments; it is connected to either the SIS or CCS to provide signal conversion there. Horbiger has never heard of it. As independent control systems, DCS, SIS, and CCS have similar network structures. However, since DCS is a large-scale system, both SIS and CCS communicate with DCS, transmitting data to it; this data is then displayed on DCS screens or uploaded to the factory’s information network.