| 摘要 |
PURPOSE:To gather data in a high speed, by discriminating the threshold value of an input value and holding this value, and adding information by which holding and holding reset are discriminated to data. CONSTITUTION:Transitional data generated from each measuring point of a plant is gathered by each analog input device 2. These analog data are converted to digital quantities by converters 3, and their threshold values are detected by maximum and minimum detecting devices 4. It is discriminated in an extreme value generation detecting device 5 whether these extreme values exceed a limit value or not. When the extreme value exceeding the limit value is detected by the device 5, a signal A is sent from the device 5 to an operating device 7. When receiving the signal A, the device 7 holds threshold values, which are stored in devices 4 beforehand, in a data holding device 6. When the device 7 does not receive the signal A, the device 7 performs another processing and takes in data simultaneously with signal reception. Thus, only normal threshold values are stored in a storage device 8. A reset signal B is sent only to devices 6 where extreme values are held. |
