| 摘要 |
PURPOSE: An input/output module of a PLC is provided to process an input/output signal of a predetermined scope using one hardware and to process the other scopes using a software scale function. CONSTITUTION: An analogue signal being inputted through an input unit(31) is amplified as a predetermined level in an amplifying unit(32) and converted into a digital signal through an A/D converter(33). A micro processor unit(34) reads the converted digital signal. An input scope of a PLC module is exampled as 0¯20mA and 4¯20mA, and a scope of a data read of the micro processor unit(34) is exampled as 0¯4000. The input scope selection is performed in the micro processor unit(34) using a software. That is, the converted value obtained through a hardware is scaled in accordance with a predetermined program and an input scope thereof is set. For example, if the input scope is 0¯20mA, inputted full scale is used. If the input scope is 4¯20mA, the value is scaled properly in accordance with the program.
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