Method and device for automatically identifying thermocouple type, temperature expansion module and temperature measurement system

Abstract

The invention discloses a method for automatically identifying the type of a thermocouple, which is applied to a temperature expansion module connected to a PLC. The method includes the following steps: when the temperature expansion module is powered on, automatically identifying and connecting to the temperature expansion module The type of the thermocouple; according to the type of the identified thermocouple, obtain the index corresponding to the type, and use the thermocouple and the index to measure the temperature of the measurement object. The invention also discloses a corresponding device, a temperature expansion module and a temperature measurement system. By implementing the technical scheme of the invention, the accuracy of temperature measurement of the measured object can be improved.

Description

technical field [0001] The invention relates to the field of programmable logic controllers (Programmable Logic Controller, PLC), in particular to a method and device for automatically identifying thermocouple types, a temperature expansion module and a temperature measurement system. Background technique [0002] In the prior art, PLC is to expand I / O (Input / Output, input or output) points or functions. Generally, various I / O modules or functional modules need to be connected through an expansion bus to form a PLC control system. The expansion bus communicates with I / O modules or function modules. [0003] An expansion bus such as a serial peripheral interface (serial peripheral interface, SPI) or a controller area network bus (Controller Area Network, CAN) is used between the existing PLC and the expansion module for connection and communication. [0004] When using PLC to collect the temperature of the measured object, a temperature expansion module is generally used, an...

AI Technical Summary

Problems solved by technology

There are some disadvantages in this way, for example, when the identification of the thermocouple used is vague, it is impossible to know the type of thermocouple, so that the setting of the DIP switch cannot be completed

At the same time, in other cases, for example, due to human identification errors or wrong setting of the DIP switch, the measurement of the temperature module will not match the type of the thermocouple, which will cause errors or inaccuracies in temperature measurement.

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