Decentralized control system and shutdown control apparatus

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.

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.