Abstract: A method for monitoring the operation of a plurality of programmable devices in a system which controls the programmable devices, and corresponding apparatus for monitoring the same. The employs two CPUs. One of the CPUs is controlled to communicate with the programmable logic controller of the system, specifically, to process devices read from the PLC, and to return the result to a two-port memory. The other CPU is controlled to read the result from the two-port memory and display it on the CRT, thus enabling a monitor display, which displays the operation of the programmable device, to have a fast response time.

Abstract: A "programless" control method and an apparatus therefor which pre-stores the device numbers of input devices that are changed in response to the manual or external-controlled operation of a controlled object in accordance with a desired sequence control procedure. The results of the changes are stored in order in a transition condition storing table as transition conditions. Also, data input from external equipment and intended to be output to the controlled object as operation step data is pre-stored in an operation step storing table in correspondence with such transition conditions. Finally, in operation, the transition conditions are read from the transition condition storing table in storage order and they are compared with the current states of the input devices when the sequence control of the controlled object is executed.

Abstract: A process for manufacturing clad metal tubing from two different types of metals having different deformation resistances is disclosed. The process comprises preparing a combined billet having two blank pipes arranged concentrically with each other, the pipes being made of different metals, and applying hot extrusion to the billet while adjusting the heating temperature of the pipe such that a pipe of the metal having a higher deformation resistance is heated to a higher temperature.