Three Point Control - Feedback (T6)
Three-point control with feedback
FB(IN := REAL1, FBK:= REAL2, TRUN:= TIME1, TOVER:= TIME2, DX:= REAL3, CLOSE=> BOOL1, OPEN=>BOOL2);
The block converts a 0...100 % signal to opening and closing pulses to control a three-point peripherial, such as a valve or damper actuator. To determine the real actuator position, a feedback signal is used.
||Insensivity to input signal (0...100 %)
||Feedback signal (0...100 %)
||Input signal (0...100 %)
||Extra travel time behind fully open or fully closed position for safe opening or closing
||Travel time between fully open and fully closed positions (0 to 100 % or back)
||Command to open
||Command to close
This block is useful for valves which provide analogue position feedback signal 0..10 V or resistance - the signal is brought to the FBK input, and the block controls over the OPEN and CLOSE signals so as the FBK signal is equal to IN. It is, actually, a controller trying to keep the FBK signal the same as IN.