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.

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：US4086570A

公开(公告)日：1978-04-25

申请号：US674915

申请日：1976-04-08

申请人： Yutaka Wakasa ,  Hisayuki Uchiike

发明人： Yutaka Wakasa ,  Hisayuki Uchiike

IPC分类号： H02P7/288 ,  G05B23/02 ,  G05F1/56 ,  H02H3/12 ,  H03K17/082 ,  H03K17/60 ,  H04Q9/16

CPC分类号： H02H3/12 ,  H03K17/0826 ,  H03K17/60

摘要： A control system of the type used in process control and comprising a controller which provides a control signal on a signal line, and a DC output circuit for converting the control signal on the signal line into a DC current output signal varying in a range of, e.g., 4 to 20 milliamperes, which is supplied to a current loop including one or more load devices. The control system is characterized by open circuit detecting means for detecting an open circuit condition in the load current loop by detecting the fall of the DC current output signal below a predetermined minimum value, and shorting means in the DC output circuit for shorting the signal line in response to detection of an open circuit condition. Level detecting means are provided for detecting the shorting of the signal line, and thus an indication of an open-circuited load condition may be supplied back to the controller without requiring added signal carrying lines.

摘要翻译： 一种用于过程控制的类型的控制系统，包括在信号线上提供控制信号的控制器，以及用于将信号线上的控制信号转换成在其范围内变化的直流电流输出信号的DC输出电路， 例如4至20毫安，其被提供给包括一个或多个负载装置的电流回路。 控制系统的特征在于开路检测装置，用于通过检测低于预定最小值的直流电流输出信号的下降来检测负载电流回路中的开路状况，以及用于使信号线短路的直流输出电路中的短路装置 响应于检测到开路状况。 提供了用于检测信号线短路的电平检测装置，因此可以向控制器提供开路负载状态的指示，而不需要附加的信号携带线路。

公开(公告)号：US3959772A

公开(公告)日：1976-05-25

申请号：US587619

申请日：1975-06-17

申请人： Yutaka Wakasa ,  Hisayuki Uchiike ,  Koju Kataoka ,  Yasuro Takiura

发明人： Yutaka Wakasa ,  Hisayuki Uchiike ,  Koju Kataoka ,  Yasuro Takiura

IPC分类号： G08C19/22 ,  H04Q9/14

CPC分类号： G08C19/22

摘要： A signal transmission system of the type used in process control systems for conveying a signal between a field telemetering instrument and a central controller, or between a central controller and a process control device. The signal transmission system is arranged with a transmitter accepting an input signal, a transmission line for carrying a transmission signal, and a receiver receiving the transmission signal and developing an output signal.In accordance with the invention, converter means in the transmitter develop a pulse width signal with a duration corresponding in a predetermined manner to the value of the input signal, and means in the transmitter provide the transmission signal (e.g., a current signal) with two states (e.g., opposite polarities), one of which has a duration corresponding to the duration of the pulse width signal. Means in the receiver provide the output signal with a duration corresponding to the duration of the one transmission signal state, which corresponds in turn to the value of the input signal, and can be used for conversion to digital or analog form. Means in one of the transmitter or receiver supplies power for the transmission signal, and means in the other of the transmitter or receiver derives operational power, e.g., for the telemetering instrument, from the transmission signal. The signal transmission system thus is able to convey signals with less susceptibility to noise, while at the same time retaining the ability to convey operational power.

摘要翻译： 用于在现场遥测仪器和中央控制器之间或在中央控制器和过程控制装置之间传送信号的过程控制系统中使用的信号传输系统。 信号传输系统布置有接收输入信号的发射机，用于承载传输信号的传输线，以及接收发射信号的接收机和显影输出信号。