Abstract: In order to provide a method for reliably detecting that an operation device, such as a sensor or an actuator, is connected to a proper connector of a control device, a connection detecting method includes the steps of reading an identification signal of the operation device, comparing the identification signal with a predetermined signal assigned to the operation device at the control device, and determining if the identification signal matches the predetermined signal. The system also includes a step of sending a connection failure warning after the determining step is repeated for predetermined times.

Abstract: In order to provide a method for reliably detecting that an operation device, such as a sensor or an actuator, is connected to a proper connector of a control device, a connection detecting method includes the steps of reading an identification signal of the operation device, comparing the identification signal with a predetermined signal assigned to the operation device at the control device, and determining if the identification signal matches the predetermined signal. The system also includes a step of sending a connection failure warning after the determining step is repeated for predetermined times.

Abstract: In an information retrieval apparatus having a data register, a plurality of first key registers, a second key register and a comparator for comparing the content of the data register and the content of one of the key registers and producing a comparison result signal for use of the information retrieval, separate retrieval conditions are established for a number of information data constituting records, and the first key registers store different ones of the retrieval conditions and a second key register stores the remaining ones of the retrieval conditions one after another in such a manner that the second key register is updated every time when a new retrieval condition is stored therein.

Abstract: A multiple virtual space control in a multiple virtual storage system having an address translation table used to translate a logical address to a real address, a control register for holding a start address of the address translation table or a space identifier (hereinafter represented by address translation table start address) and an address translation buffer containing a pair of logical address and real address and an address translation table start address for translating a logical address to a real address, in order to update the content of the control register to switch the virtual space. A group identifier comprising a plurality of bits for identifying an area common to a group of virtual spaces is added to an entry of the address translation table, an entry of the address translation buffer and the control register.