【Daily Question 20090329】What are the operating systems for DCS? Which one do you think is the best?

I just started working, and I don’t know much about DCS yet; I only know that it is a distributed control system that sends signals to the control room – it’s quite modern. I don’t know what the operating system involves, so I don’t know how to answer that question. I’ll sit down and look at others’ responses to learn from them.

　　The DCS system (Distributed Control System) is a comprehensive control system that emerged with the growing automation of modern large-scale industrial production and the increasing complexity of process control requirements. It is the result of the integration of computer technology, system control technology, network communication technology, and multimedia technology, and it offers a user-friendly graphical interface as well as powerful communication capabilities. It is modern equipment for achieving process control and process management. 　　For different industries and projects, and based on thorough research into computer technology, network technology, application software technology, and signal processing technology, various Distributed Control Systems (DCS) are utilized to carry out engineering design, configuration, complete supply of equipment, on-site commissioning, performance testing, and evaluation in a high-quality and standard-compliant manner, thereby delivering practical and feasible technical solutions. 　　Overview of the system’s main technologies ※The system mainly consists of field control stations (I/O stations), data communication systems, human-machine interface units (operator station OPS, engineer station ENS), cabinets, power supplies, etc. The system features an open architecture that provides multiple layers of open data interfaces. 　　※Hardware systems feature high reliability in harsh industrial environments, easy maintenance, and advanced technology. The software platform with localized interface at the underlying level possesses powerful processing capabilities, offers the ability to easily configure complex control systems, and provides support for users to develop their own advanced control algorithms ； Easy to configure and easy to use. It supports multiple fieldbus standards to meet future expansion requirements. 　　※The system is designed with appropriate redundancy configurations and self-diagnosis capabilities up to the module level, ensuring a high degree of reliability. A failure in any component within the system will not affect the operation of the entire system. 　　※The system’s parameters, alarms, self-diagnosis, and other management functions are highly concentrated on the CRT for display and printed on a printer, resulting in a truly functional and physical decentralization of the control system. 　　※The availability of the entire system is at least 99.9% ； The system’s average time between failures is 100,000 hours, enabling comprehensive monitoring in various fields such as nuclear power, thermal power, cogeneration, petrochemicals, chemicals, metallurgy, and building materials. 　　※“The concept of a “domain”. Large control systems are divided into several relatively independent subsystems using high-speed real-time redundant networks; each subsystem forms a domain. The various domains share management and operation data, while within each domain there is a fully functional DCS system, thereby better meeting the needs of users. 　　※Reliability, openness, and advancement of network architecture. At the system operation level, redundant 100Mbps Ethernet is used ； At the control layer, redundant 100Mbps industrial Ethernet is used to ensure system reliability ； At the field signal processing layer, a 12Mbps PROFIBUS bus connects the central control unit to the various field signal processing modules. 　　※Standard Client/Server architecture. The operation layer of the MACS system adopts a Client/Server architecture. 　　※An open and reliable operating system. The operating layer of the system uses the WINDOWS NT operating system ； The control station utilizes the mature embedded real-time multitasking operating system QNS to ensure the real-time performance, security, and reliability of the control system. 　　※Standard control configuration software. Any monitoring and control requirements can be met. 　　※Scalability and adaptability. Ensure cost-effectiveness. One of our company’s main products is chlor-alkali, and the control of this production process is carried out using a DCS operating system; we use Yokogawa’s DCS. We also have PLC control systems, but it’s only by comparing them that one can realize the advantages of DCS in terms of sophistication. Last edited by Seeking Help on 2009-3-26 09:33]

I’m not sure whether the moderator is asking about the operating system of the HMI operator station, or the operating system built into the CPU of the DCS. The operating system of the DCS monitoring station and HMI operation station is currently, predominantly, the Windows platform. In mainstream C/S architecture systems, Win2000 and XP are typically used as operator stations, while Win2000 Server and 2003 Server serve as servers. No manufacturers have yet responded regarding 64-bit systems and Win2008 Server. Many older-generation systems, as well as some of the currently used mainstream classic systems, still use Unix. For example, the T-XP from SPPA, a company under Siemens PG, is SCO Unix. The current mainstream T3000 is for the Windows platform. Emerson-Whirlpool’s Automation can use Sun’s Solaris Unix, or it can also use WinXP. The I/As of Invensys-Foxboro can use Sun’s Solaris Unix, or it can also use WinXP. ABB’s previous generation models, the AC450 and AC460, could run either HP’s HP-UX Unix operating system or WinXP 2000. The current 800XA model can only be used with Windows. As for the advantages and disadvantages. . . Relatively speaking, Unix systems are closed, with dedicated hardware. Spare parts are very expensive. But it has high safety and good stability. Look, almost all of the systems currently used in nuclear power applications are based on the Unix platform. Several foreign nuclear power systems for which Foxboro won bids in 2009 still use the Unix system rather than Windows. There’s another issue: almost all Unix platforms do not support OPC at all. The core mechanism of OPC is Com/DCom. However, Com and DCom are mechanisms specific to Windows, and Unix does not support them at all. For the Windows platform, PCs can be used; they have a high degree of hardware versatility and are inexpensive. Openness. Maintenance is also simple. Openness is well reflected in communication, as evidenced by DDE, OPC, ODBC – all of which are well supported by Windows. It is worth mentioning that Siemens uses SCO Unix. Development and updates for this operating system software have been halted. However, although SCO’s Unix is indeed Unix, it is based on a PC platform, and Siemens uses exactly that PC-based version. I mean. He can use ordinary DELL or HP computers, rather than specialized Unix workstations such as SUN or HP. The hardware cost is slightly lower. Maintenance is also convenient, as the software platform is still Unix after all, and it remains closed.