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Help!! For the Yokogawa VP system, it is required to enter 0–4 in the operation interface to select the corresponding fans numbered 1–4; these 4 fans correspond to 4 channels respectively, with 0 indicating that no fan is selected. A PID controller is used for control. Whichever one is selected will start to adjust automatically! Only one can be selected at a time; when switching, it is necessary to gradually reduce the load to 0, while the newly selected fan should have its load increased gradually from zero. How should this be done?
The operation of selecting the fan can be achieved through the PBS5C function block and its faceplate. Then, in CALCU, it determines the selected fan; the mode of the selected one is set to AUTO, while that of the unselected one is set to MAN. When switching, create a small program for decrementing and accumulating.
This post was last edited by diyemei on 2015-8-21 at 15:31; it can also be achieved using SW-91 and sequential control, with the rest remaining the same