公开(公告)号：US4074354A

公开(公告)日：1978-02-14

申请号：US692329

申请日：1976-06-03

申请人： Mutsuaki Nakagawa ,  Yutaka Wakasa ,  Hisayuki Uchiike ,  Susumu Nagata

发明人： Mutsuaki Nakagawa ,  Yutaka Wakasa ,  Hisayuki Uchiike ,  Susumu Nagata

IPC分类号： G05B11/00 ,  G05B7/02 ,  G05B11/01 ,  G05B15/00 ,  G05B15/02 ,  G05B19/18 ,  G05B19/408 ,  G05B23/02 ,  G06F3/00 ,  G06F11/00 ,  G06F3/04

CPC分类号： G05B15/02

摘要： A process control system of the type arranged to accept sensing signals from field sensing devices, to digitally process data represented thereby, and to supply control signals to field control devices. The system is characterized by a centralized maintenance backup system for supplying backup control signals to selected field control devices while their normal control signals are interrupted during servicing of various system components, e.g., signal conversion units. A maintenance backup device, centrally located at a control station, includes means for providing an adjustable backup control signal, a selector unit having jack terminals connected through prewired leads to a plurality of field control devices, and jack plug means for connecting the backup control signal means to a selected jack terminal and the field control device corresponding thereto. Servicing of circuit boards used, e.g., for signal conversion purposes, is facilitated by providing ready and simplified access to the different field control devices through the selector unit, and by utilizing data available at the system's central operating location to continue control of the field device in the manner prescribed by the digital processing unit.

公开(公告)号：US4082942A

公开(公告)日：1978-04-04

申请号：US812060

申请日：1977-07-01

申请人： Osamu Tada ,  Mutsuaki Nakagawa ,  Hiroshi Mori ,  Yutaka Wakasa ,  Koju Kataoka ,  Tadanari Inoue ,  Hisayuki Uchiike

发明人： Osamu Tada ,  Mutsuaki Nakagawa ,  Hiroshi Mori ,  Yutaka Wakasa ,  Koju Kataoka ,  Tadanari Inoue ,  Hisayuki Uchiike

IPC分类号： G05D27/02 ,  H03M1/50 ,  H03K13/20

CPC分类号： G05B19/0423 ,  H03M1/504 ,  G05B2219/21137 ,  G05B2219/25392 ,  G05B2219/2609

摘要： A process control system of the type arranged to accept varied forms of analog sensing signals from field sensing devices, to digitally process data represented thereby, and to supply varied forms of analog control signals to field control devices. The system is characterized by signal converter means which convert data between the varied analog forms generated by the field devices and a standard form of intermediate signal, e.g., a pulse-width signal, which carries data as a function of duration. The intermediate signals facilitate signal transmission, editing, and isolation, and permit the process control system to have a simple, noise-free, easily adaptable structure. Digital interface means then convert data between the intermediate signals and digital signals in a form suitable for use by digital data processing means.