Publish date: 28.05.2019
Distributed Control system 8S with improved safety requirements is an adaptable solution for a wide range of tasks of managing hazardous technological processes. Our systems have found applications at the facilities of the energy, petrochemical and machine-building industries. It is recognized as a safe and fault-tolerant process control system. The system itself is a modular, easily configurable set of hardware which can be expanded and scaled throughout the entire lifecycle.
Distributed control system and Automated control system is a mix of technological and software solutions, which is designed for control of technological equipment in industrial facilities. Automated data collection, data processing and technological process control require special solutions. In this case, ACS and DCS are built according to a hierarchical system and have a multistage structure.
There are three main levels:
- The lowest level is known as the field level or physical input/output channel level. Sensors, measuring devices, actuators. Technical equipment at this stage ensures the collection of the required analogue and discrete information from the main technological equipment:
- Temperature, pressure, viscosity and etc
- Equipment condition (pump): condition, power availability, preparation and etc
- TSensors for technological parameters
- Outgoing signal converter.
- The middle level or secondary level is known as the control level. It is a process logic controller level. Programmable logic controllers receive information from sensors, measuring devices about the state of technological process and give control commands with the programmed control algorithm for actuators like electrified valves, pump motors, electric valves and other devices.
- The top level or upper level. Operator and dispatcher stations stage level. At this level, the production process is under control: communication with lower levels, where the data collection is from, visualization and monitoring is carried out. At this level, there is a man, i.e., an operator who performs local control of technological equipment using the human machine interface (HMI). It includes: monitors, graphic panels mounted locally at automation cabinets. SCADA is used to control system mechanisms and assemblies. (SCADA- Supervisory Control And Data Acqusition).This is software used on dispatcher computers. This system provides information collection, archiving and visualization of key data from controllers. When data is received, the system automatically compares them with the set parameters and the operator will be warned about the stray from the set parameters, thus allowing him to take the necessary actions. At the same time, the system recors all operator actions and ensures operator control and security. It must also be possible to print messages on the system printer.
Typically Distributed control system must support communication with other interconnected systems, such as ESD, PLC and etc. and must also be compatible with these signals.
- Analog input 4-20 mA DC
- Thermocouple analog input (type J, K, E, R)
- RTD analog input (PT100 Ω, Trilay)
- Impulse input 0-100kHz
- Digital input – Voltage-free contacts complying with NAMUR/DIN 19234
- Analog output 4-20 mA DC
- Digital output – Relay or Voltage (24VDC)
- Modbus RTU interface for COMLI, MODBUS, freely programmable serial interface protocols
- Modbus TCP
- PROFIBUS DP
- PROFINET IO
- FOUNDATION Fieldbus
Duplication of individual system modules should be used to increase system reliability. In a duplicated system, if one of the duplicate module fails, the processes on the terminal are not stopped. The system must be protected against switching to damaged or malfunctioning modules. In case of distributed control system or automated control system damage, an alarm system must cause a message to operators. Service and replacement of faulty modules are replacing or adding components without stopping or shutting down the system. The application of duplication of input/output modules must be set individually. Duplication of the Distributed control system and automated control system must include:
- Non-duplicate operator stations must use the same software that performs the same function
- Duplicate system communication and transmission networks
- Duplicate processors controlling terminal processes
- Duplicate network with other systems
- Duplicate AI/AO modules used for control functions.
Automated control system and distributed control system allow You to solve many tasks oriented to technological process optimizations.