| 摘要 |
PURPOSE:To ensure an accurate control of the flow rate or the like and at the same time detect the fault of the integrator in the process control, by giving an integral operation to the input deviation signal by the arithmetic circuits of two systems and giving a correction to the output of each integrator to a constant level. CONSTITUTION:The deviation signal of the set and detected signals is supplied through terminal A and then integrated through integrators 11 and 12. And each integral output is added at adder circuit 13, and the control subject is worked by the added output obtained at terminal B. In this case, each integral output is led to correcting circuit 14, and thus the correction signal is supplied to each integrator's input to secure a difference of zero between both outputs if any. Furthermore, the quantity of the correction signal reached the fixed level is detected by detecting circuit 15, and the alarm is produced by the detection output. As a result, the fault can be detected automatically for each integrator. |
