Abstract: When a read command is sent from a command device to a communication control apparatus, a communication program refers to a PLC address table and cites a PLC address, including a communication protocol of the PLC identified by the read command. The communication program translates the read command using a protocol translation table and transmits the translated read command to the PLC. The communication program translates data read from the PLC using the protocol translation table, and stores the translated data in a tag file.

Abstract: Method and apparatus for inspecting a surface having a photosensitive layer on a wide film web from which lateral margins are slit away, by detecting defects of the photosensitive layer of the surfaces of the lateral margins. The intensity of a line of light which is projected onto a lateral margin of the web is modulated by the surface of the lateral margin and received by reflection by a line sensor for producing an analog video signal which in turn is converted into two binary signals of high and low output levels. From the combination of the two binary signals, the presence of a defect is detected, because the intensity of the modulated reflected light will vary from a value characteristic of the absence of a defect.

Abstract: An apparatus for measuring the thickness of a roll winding on or unwinding from a core during winding or unwinding of a web, comprises a first detector having a beam projector and a beam receiver which are arranged along the core at opposite ends of the roll for detecting a predetermined thickness of the roll with a rough accuracy. A second detector having a beam projector and a linear array sensor is provided, for detecting the roll thickness with high accuracy. When the first detector detects a predetermined thickness of the roll, the second detector, which is supported on an arm carrying a positioning roller, is placed in operative position by pressing the positioning roller against the core and detects the thickness of the roll according to the position on the linear array sensor of the beam reflected from the surface of the roll.