| 摘要 |
<p>PURPOSE:To reduce the load of a host computer and to speed up processing in a trend graph plotting device for time-sequentially plotting status data sequentially inputted by a plant monitoring computer or the like as trend data. CONSTITUTION:A data judging part 23 judges match/mismatch between trend data inputted to a data input part 21 in a host computer 20 at a fixed time interval and a preceding input data value in each input of trend data and successively sends only data judged as mismatch to display device 30. Data received by a display control part 31 are converted into a display coordinate system and displayed on a plotting point corresponding to a time sequence on a display part 33 and stored in a trend data storing part 34, and if trend data are not received from the host computer 20 for a fixed time or more counted by a timer device 32, the data received in the preceding time and stored in the storing part 34 are read out as current receiving data and displayed on the succeeding plotting point of the display part 33.</p> |
