Method for realizing automatic calibration of PLC analog input and output module channel

Abstract

The invention provides a method for realizing automatic calibration of a PLC analog input/output module channel. According to the technical scheme, a process instrument, a switch matrix, an analog input/output module, M channels and an upper computer are included. And the upper computer issues configuration to the process instrument, reads data, issues configuration to the switch matrix, and receives calibration results of each channel of the analog quantity input/output module. The upper computer evaluates the calibration progress of each channel according to the calibration result of the analog quantity input/output module and the read data of the process instrument, and outputs corresponding issuing configuration according to the progress, so that the process instrument adjusts the analog quantity signal output/measured by the process instrument, and the switch matrix adjusts the communication path of the process instrument; and further enabling the analog input/output module to continue to execute the calibration program until all channels of the module are calibrated. According to the invention, wiring errors, key errors and reading errors possibly caused by manual operation can be avoided; the influence of different contact effects caused by manual plugging each time on the channel calibration effect can be reduced; the deviation of channel calibration caused by reading when the system state is not stable can be reduced; the multi-channel calibration efficiency of the analog input/output module can be improved.

Description

technical field [0001] The invention belongs to the technical field of industrial process control, and in particular relates to a method for realizing automatic calibration of a channel of a PLC analog input and output module. Background technique [0002] All PLC analog input / output modules need to be calibrated for the channel before leaving the factory. Only the channel-calibrated analog input / output modules can meet the precision requirements required in the industrial control field, and can be applied to actual analog acquisition and control scenarios such as metallurgy, chemical industry, electric power, medical treatment, transportation, communication, light industry, etc. go. [0003] The practice of conventional PLC analog input / output channel calibration is: use the process instrument to connect a channel of the analog output / output module, manually set the analog signal type, set the calibration point, execute the calibration procedure, and judge the calibration ...

AI Technical Summary

Problems solved by technology

The limitations of this approach are: manual operation may cause wiring errors, key errors, and reading errors; the different contact effects caused by each manual plugging and unplugging will affect the channel calibration effect; the readings when the system state is not stable will affect the channel calibration. Introduce bias; calibration of multiple channels of analog input / output modules is inefficient due to repeated plugging and unplugging of switching channels

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