Decentralized control system and shutdown control apparatus
First Claim
1. A decentralized control system configuring a network between plural field devices for measuring and controlling a controlled object and an upper-level apparatus for communicating data to said field devices and controlling said field devices, and forming a control loop among said devices, whereinsaid field device has a normal communication means for communicating with other devices in a normal operation mode;
- andan emergency communication means for communicating with other devices in an emergent operation mode,wherein said normal communication means and said emergency communication means use their own communication signals; and
said emergency communication means operates in an asynchronous communication mode.
1 Assignment
0 Petitions
Accused Products
Abstract
In a decentralized control system configuring a network between plural field devices for measuring and controlling the controlled objects and plural upper-level apparatus for communicating data to the field devices and controlling the field devices, and forming a control loop among the devices, in which the field device has a normal communication means for communicating with other devices in a normal operation mode, and an emergency communication means for communicating with other devices in an emergent operation mode, in which the normal communication means and the emergency communication means use their own communication signals and the emergency communication means operates in an asynchronous communication mode. In addition, on the network, a shutdown control means is formed for transmitting a shutdown command signal to the shutdown target control device if necessary by detecting the abnormal state of the individual devices.
100 Citations
16 Claims
-
1. A decentralized control system configuring a network between plural field devices for measuring and controlling a controlled object and an upper-level apparatus for communicating data to said field devices and controlling said field devices, and forming a control loop among said devices, wherein
said field device has a normal communication means for communicating with other devices in a normal operation mode; - and
an emergency communication means for communicating with other devices in an emergent operation mode, wherein said normal communication means and said emergency communication means use their own communication signals; and said emergency communication means operates in an asynchronous communication mode. - View Dependent Claims (2, 3, 4, 5, 6)
- and
-
7. A decentralized control system configuring a network between plural field devices obtaining electric operation power from a transmission path for measuring and controlling a controlled object and plural upper-level apparatus for communicating data to said field device and controlling said field device, and forming a control loop among said devices, further comprising
a shutdown control means formed on said network for detecting an abnormal state of an individual device and, if necessary, supplying a shutdown command to a shutdown target control device for which a shutdown operation is required, said shutdown control means and said shutdown target device being connected by an independent control signal line other than said transmission path.
-
14. A shutdown control apparatus arranged in a decentralized control system configuring a network between plural field devices obtaining electric operation power from a transmission path for measuring and controlling the controlled objects and plural upper-level apparatus for communicating data to a field device and controlling said field device, and forming a control loop among said devices, for shutting down an individual device, further comprising
an independent control signal line other than said transmission path connected to an individual shutdown target device requiring shutdown control; -
an abnormality detection means for detecting an abnormal state of an individual device on said network; and a shutdown control circuit for sending a shutdown command through said control signal line on the basis of a result of detection by said abnormality detection means, said shutdown control circuit establishing connection between the field device requiring shutdown and a shutdown command dedicated line. - View Dependent Claims (15)
-
-
16. A shutdown control apparatus arranged in a test sample conveying system,
said test sample conveying system forming a control loop with the individual devices, and configuring a network through a transmission path between a field device composed of a motor for driving a conveying system or a sensor for detecting a position of a conveyed object, and an upper-level apparatus for communicating with said field device and controlling said field device, further comprising, for shutting down an individual device, a control signal line connected to said field device including the motor; -
an abnormality detection means for detecting an abnormal state of an individual device on said network; and a shutdown control circuit for sending a shutdown command through said control signal line for stopping said motor on the basis of a result of detection of said abnormality detection means, said shutdown control circuit establishing connection between the field device requiring shutdown control and a shutdown command dedicated line.
-
Specification