Abstract: A networking PLC core comprising a program for uniting a programmable logic controller function to a fourth transport layer and a fifth session layer in compliance with network communication specifications in an OSI reference network model embedded therein, and a single or plural ICs or modules for exclusive use which are configured to store, manage and execute the program.

Abstract: A rolling bearing has a sensor unit disposed on one of the opposite circumferential surfaces of a fixed ring of the bearing. The sensor unit includes two strain gauges disposed on the circumferential surface of the fixed ring, one strain gauge extending in the circumferential direction fo the fixed ring and the other strain gauge extending in the axial direction of the fixed ring. Preferably the strain gauges are arranged to overlap with each other and to cross at right angles or obliquely to each other. A plurality of performance characteristics of the bearing are detected on the basis of output signals from the two strain gauges. The detection of the performance characteristics enables the rolling bearing to be monitored during operation with respect to applied load, the rotational speed and acceleration of a rolling ring thereof, a rise in temperature thereof and an abnormal vibration thereof.