An apparatus for extracting common command information from programmable logic controller (PLC) ladder information according to the present invention may include: a logic information extracting portion configured to extract control logic information from XML information converted from PLC ladder information; and a common command converting portion configured to convert the control logic information extracted by the logic information extracting portion into common command information, wherein the logic information extracting portion is configured to extract, from the XML information, the control logic information in the form of a block obtained by grouping units that respectively represent contacts and lines constituting the PLC ladder information according to an AND condition and an OR condition.

Provided is a technology with which it is possible to access a function unit to be accessed without ascertaining an IP address of the function unit. Provided is a unit comprising: a communication unit for relaying a communication between an external device connected to a first network and another unit connected to a second network; a setting unit for acquiring address information of the other unit in the second network from the other unit and generating setting information in which the address information is associated with an identifier which substitutes for the address information; and a link information generation unit for generating, on the basis of the identifier, link information used to access information on the other unit from the external device.

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.

Systems, methods, and apparatuses are provided for a path affinity engine that may work in the background to discover route information needed to connect industrial control components to control level data using tag names. Connections may be established dynamically through the path affinity engine, thereby simplifying the commissioning process and allowing connections to be made on an as needed basis. Accordingly, discovery of tag locations at runtime may be permitted, and implementing hardware changes in industrial control environments may be greatly simplified.

Provided is a technology with which it is possible to access a function unit to be accessed without ascertaining an IP address of the function unit. Provided is a unit comprising: a communication unit for relaying a communication between an external device connected to a first network and another unit connected to a second network; a setting unit for acquiring address information of the other unit in the second network from the other unit and generating setting information in which the address information is associated with an identifier which substitutes for the address information; and a link information generation unit for generating, on the basis of the identifier, link information used to access information on the other unit from the external device.

An apparatus for extracting common command information from programmable logic controller (PLC) ladder information according to the present invention may include: a logic information extracting portion configured to extract control logic information from XML information converted from PLC ladder information; and a common command converting portion configured to convert the control logic information extracted by the logic information extracting portion into common command information, wherein the logic information extracting portion is configured to extract, from the XML information, the control logic information in the form of a block obtained by grouping units that respectively represent contacts and lines constituting the PLC ladder information according to an AND condition and an OR condition.