| 摘要 |
PROBLEM TO BE SOLVED: To detect an abnormal state of a communication function for setting a manipulated variable lower-limit value OL and a manipulated variable upper-limit value OH by a lower side control device.SOLUTION: A lower-side temperature controller 2 includes: a limit processing part 21 which limits a manipulated variable MV2 calculated by a lower-side control arithmetic part 20 to a value equal to or larger than a manipulated variable lower-limit value OL and equal to or smaller than a manipulated variable upper-limit value OH; a test upper/lower-limit value setting part 23 which calculates at least one of a test manipulated variable lower-limit value OL a prescribed quantity different from the manipulated variable lower-limit value OL and a test manipulated variable upper-limit value OH a predetermined quantity different from the manipulated variable upper-limit value OH at test conduction timing and then sets it as a value to be used by the limit processing part 21; and an alarm output part 24 which outputs an alarm if the set manipulated variable lower-limit value OL or manipulated variable upper-limit value OH are not updated to values different from the value that the test upper/lower-limit value setting part 23 sets after at least one of the manipulated variable lower-limit value OL and manipulated variable upper-limit value OH is set.SELECTED DRAWING: Figure 1 |
