What do industrial automation control instruments mainly refer to?

Industrial automation instruments mainly include eight types of instruments and industrial computers, such as transmission, conversion, calculation, display, setting, adjustment, assistance and execution. These include:

The instrument includes:

1. conversion instrument: convert various measured parameters (adjustment parameters in automatic adjustment system) into unified standard signals for indication, recording or adjustment. The transmission unit mainly includes pressure transmitter, differential pressure transmitter, flow transmitter, temperature transmitter, temperature difference transmitter and liquid level transmitter.

2. Instrument conversion: convert the output signals of various testing instruments or other series of instruments into standard signals. The conversion unit includes DC millivolt converter, frequency converter, impedance converter, pneumatic converter, etc.

3. Computing instrument: it can perform operations such as addition, subtraction, multiplication, division and square. Several standard signals. It is suitable for multi-parameter comprehensive adjustment, and can correct and calculate the flow signal according to temperature and pressure. For example, an adder and a subtractor can add and subtract four unified signals.

4. Display instrument: display, record and accumulate measurement parameters for the operator to operate and monitor the regulating system.

5. Given instrument: it is divided into proportional setter and alarm setter, which are used for proportional adjustment system and acousto-optic alarm respectively.

6. Adjust the instrument: compare the adjusted signal with the given signal, calculate the deviation value according to certain adjustment rules (such as proportion, integral and differential), and then output an adjustment signal to the actuator to realize the automatic adjustment of the system.

7. Auxiliary instrument: It plays a matching role in the regulating system, making the composition of the regulating system more flexible. Among them, the signal selector can select the largest or smallest signal from two or three signals as output; The signal limiter is used to limit the variation amplitude of the signal so that it does not exceed the limit requirements of a certain production process. When the change amplitude of the input signal exceeds the limit range, the output signal remains at the limit value. Safety barriers are divided into two types: detection end and operation end. Its function is to isolate the circuit reliably and prevent the high voltage accidentally entering from the power supply side from mixing into the signal circuit. At the same time, through the current and voltage limiting energy circuit, the current and voltage entering the dangerous place are limited below the safe value, so that the electric spark that may be generated by the circuit is also limited below the ignition energy of explosive gas.

8. Actuator: The signal sent by the regulating device is converted into mechanical displacement, and the valve and other actuating elements are manipulated to realize automatic regulation.

The functions of various instruments can often be combined or split. For example, the ratio regulator may include display, setting, adjustment and other types of instrument functions.

Industrial computers include:

1, distributed control system (DCS), also known as DCS (distributed control system.

2. ESD and SIS of safety interlock system

3, programmable controller PLC

4. Fieldbus system.

Generally speaking, in the case of using industrial computer, other instrument functions except transmission and execution can be replaced by computer.

In addition, there are a large number of sensors not only belonging to industrial automation instruments and equipment, such as temperature sensors and displacement sensors. And a large number of industrial on-line analytical instruments, such as on-line analyzers and fire alarms. As long as it can be used in industrial automation, it is customary to use it as an industrial automation instrument.