Control systems could be divided into three groups:
- Logical systems
- Numerical systems
- Hybrid systems
Logical systems
Logical systems are systems which communicate with neighborhood due to binary signals (yes, no or 1, 0 etc.) Information by these systems are made by Boolean algebra rules, and so called Boolean or binary systems. Binary system can be implemented by contact or contactless switching.
Binary systems can be implemented in different technologies, which are applied to logic functors. E.g. in control schemes, using transistors and even housing: Fixed logic, FPGA, program uC, DSP, PC, Control schemes.
Electrical control schemes are drawings in which is shown the control and power circuit. Elements of the main circuit are controlled by switches, power contacts of contactors or relays. The control circuit is composed of controls such as buttons, switches, timers and limit switches, coils, relays or contactors. Both elements can be replaced by weak-and power electronics.
The figure is drawn diagram of the control and power circuits with simple functions. Press A control voltage is applied to the contactor coil S1 is closed. Its normally open contact connected to the 1S1 voltage appliance (lamp) Z1, while NC 2S1 Z2 appliance disconnected from the power supply. The function of the circuit is such that pressing the A button will light lamp bulb goes Z1 and Z2. Release the button and the result will be the opposite.
Independent variable, and realized two logical functions, equivalence and negation.
Numerical systems
Numerical systems are the systems, which works with arithmetical operations and are under algebraical rules. It’s mostly basic algebraical operations addition, subtraction, multiplication and division, and possibly using much more complex operations and functions. Numerical system is executed by microprocessor.
Hybrid systems
Hybrid systems are combination of logical and numerical (continuous) systems, and have special behaviour. Hybrid systems are executed by microprocessor too.