Programmable controller system for performing analog-to-digital conversion based on an adjustable conversion characteristic table

Patent metadata

Field	Value
Publication number	US-9869988-B2
Application number	US-201414888741-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 7, 2014
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

An analog input unit as an analog unit attached to a PLC includes an A/D converting unit as a first converting unit performing conversion between an analog value and a digital value according to a first conversion characteristic, a shared memory as a retaining unit retaining a conversion characteristic table indicating a second conversion characteristic of conversion between digital values, and a conversion processing unit as a second converting unit converting a digital value according to the second conversion characteristic by referring to the conversion characteristic table. The conversion characteristic table includes combinations of a first value that is a digital value and a second value that is a conversion result of the first value, the number of which corresponds to resolution of a digital value in the analog unit, and the second value of each of the combinations of the first value and the second value can be adjusted.

First claim

The invention claimed is:

1. A programmable controller system comprising:
a programmable controller that includes an analog unit; and
a conversion-characteristic-table creation device that is connected to the programmable controller and creates a conversion characteristic table, wherein
the analog unit includes
a first converter to convert an analog value to a first digital value based on a first conversion characteristic, and
a second converter to convert the first digital value to a second digital value based on a second conversion characteristic obtained from the conversion characteristic table, the conversion characteristic table comprising the first digital value and the second digital value,

the conversion-characteristic-table creation device comprises
a display to display a first graph indicating a conversion characteristic obtained by combining the first conversion characteristic and the second conversion characteristic indicated in the conversion characteristic table, and display a list of candidate graphic shapes, and
an adjuster to adjust, in response to a graphic shape being selected from the list of candidate graphic shapes, the second digital value of the conversion characteristic table to reflect the selected graphic shape, and control the display to display a second graph based on the adjusted second digital value.

2. The programmable controller system according to claim 1 , wherein
the analog unit further includes
an analog input interface to receive an input of the analog value to the analog unit; and
a bus interface that is connected to an inter-unit bus that connects units included in the programmable controller to each other,

the first converter converts the analog value input to the analog input interface to the first digital value,
the second converting unit converts the first digital value that is a conversion result by the first converter to the second digital value, and
the bus interface outputs the second digital value that is a conversion result by the second converter to the inter-unit bus.

3. The programmable controller system according to claim 1 , wherein
the analog unit further includes
an analog output interface to output the analog value from the analog unit; and
a bus interface that is connected to an inter-unit bus that connects units included in the programmable controller to each other,

the second converter converts the first digital value input from the inter-unit bus to the bus interface to the second digital value,
the first converter converts the second digital value that is a conversion result by the second converter to the analog value, and
the analog output interface outputs the analog value that is a conversion result by the first converter.

4. The programmable controller system according to claim 1 , wherein
the analog unit further includes
an analog input interface that receives an input of the analog value to the analog unit; and
an analog output interface to output the analog value from the analog unit,

the first converter includes an analog-digital converter that converts the analog value input to the analog input interface to the first digital value and a digital-analog converter that converts the first digital value to the analog value,
the second converter converts the first digital value that is a conversion result by the analog-digital converter to the second digital value,
the digital-analog converter converts the second digital value that is a conversion result by the second converter to the analog value, and
the analog output interface outputs the analog value that is a conversion result by the digital-analog converter.

5. The programmable controller system according to claim 1 , wherein
the analog unit further includes a retainer to store the conversion characteristic table, and
the retainer is a shared memory from and into which data is to be read and written by a unit controlling the programmable controller.

6. The programmable controller system according to claim 1 , wherein
the display displays data included in the conversion characteristic table, and
the adjuster receives a command to update the data included in the conversion characteristic table.

7. A conversion-characteristic-table creation device that creates a conversion characteristic table that is referred to in analog-to-digital conversion performed in an analog unit, the conversion-characteristic-table creation device comprising:
an adjuster to adjust data included in the conversion characteristic table, the data indicating a second conversion characteristic when a first conversion characteristic is used to perform conversion between an analog value and a first digital value and the second conversion characteristic is used to perform conversion between the first digital value and a second digital value; and
a display to display a first graph indicating a conversion characteristic obtained by combining the first conversion characteristic and the second conversion characteristic indicated in the conversion characteristic table, and display a list of candidate graphic shapes, wherein
in response to a graphic shape being selected from the list of candidate graphic shapes, the adjuster adjusts the second digital value of the conversion characteristic table to reflect the selected graphic shape and controls the display to display a second graph based on the adjusted second digital value.

8. The conversion-characteristic-table creation device according to claim 7 , wherein
the display displays the data included in the conversion characteristic table, and
the adjuster receives a command to update the data included in the conversion characteristic table.

Assignees

• Mitsubishi Electric Corp

Inventors

• Abe Hiroshi
• Ukena Satoru
• Ishida Koichi

Classifications

• G05B2219/1176

  I-O signal processing, adaption, conditioning, conversion of signal levels · CPC title

• G05B19/05 Primary

  Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts · CPC title

• G05B2219/1126

  Conversion table between original defined module address and actual physical address · CPC title

• G05B19/054 Primary

  Input/output · CPC title