In this section we try to explain many basic concepts about design of control systems that are not always clear and recommend some good practices on how to make the design. There are many aspects we treat: the control panel, options for redundant architectures, design of a fail safe system, different types of logics (1oo2, 2oo2, 2oo3,…), some tips when selecting I/O modules, etc. Let us know if you are interested in a specific topic.
Why Cpt is so important?
In the process industry when we calculate the Probability of Failure on Demand (PFDavg) of a Safety Instrumented Function (SIF) we …
Dangerous failures of the SIS
When calculating Probability of Failure of a Safety Instrumented Function (SIF), the most important are the dangerous failures, as we see …
The importance of diagnostics in the SIS
The diagnostics in an Safety Instrumented System (SIS) are of crucial importance because they are the key to reduce …
The importance of common cause failures
When designing a control system, we should paid special attention to common cause failures, that is, to the factors that …
What is a Safety Instrumented Function?
The safety instrumented function is a control loop in a process or machine whose objective is safety. SIF is its …
SIL requirements – Systematic Capability, Failure Probability and Architectural Constraints.
The designer of the safety instrumented function must verify that the 3 SIL requirements of the …
Phase 7: Isolators and Terminal Blocks
In this article we discuss the options we have for isolators, converters, barriers, terminal blocks and other components (index of …
Phase 6: Power Supply and Circuit Breakers
In this article we discuss the design of 24 VDC power supply and circuit breakers (index of design phases).
6-Power …
Phase 5: Selection of HMI
In this article we discuss the selection of the HMI / SCADA (index of design phases).
5-Selection of HMI or SCADA
In medium …
Phase 4: CPU selection and Control System Architecture
In this article we discuss how to select the CPU and describe the main options for the Control …
Phase 3: Grouping and segmentation of I/Os and Racks (functional distribution)
In this article we discuss the importance of the functional distribution of I/Os, especially in …
Phase 2: Selection of I/O modules (part B)
In this article (part B) we discuss other design factors of the selection of Input / Output Modules …