| Input IN1 |
REAL (input value of 1) |
| IN2 |
REAL (input value 2) |
| F |
BOOL (select input TRUE = IN2) |
| TF |
TIME (Transition period) |
| RST |
BOOL (Asynchronous Reset) |
| Output Y |
REAL (baseline) |
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FADE is used to switch between 2 inputs IN1 and IN2 with a soft transition. The switching time is specified as TF. An asynchronous reset (RST) resets the module without delay to IN1 if F = FALSE or IN2 when F = TRUE. A switching operation is triggered by a change in the value of R. Then it switches within the time TF between the two inputs. The switchover will mix the two entrances during the changeover. At the beginning of switching at the output are at 0% of the new value and 100% of the old value passsed. after half the transfer time (TF/2) the output has 50% each of the two input values (Y = in1* 0.5 + in2 * 0.5). after the time TF is then the new output value to 100% available. |
| During the switching of the output Y is |
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Y = TU/TF * IN1 + (1 - TU/TF) * IN2. |
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TU is the time elapsed since the start of the switchover. |
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Since the output of FADE is dynamically calculated, the device can also be used to switch dynamic signals. The switch is divided into up to 65,535 steps, which can be limited by the cycle time of the PLC. A PLC with a cycle time of 10ms and a TF of a second is only in 1s/10ms = 100 steps to change channels. |
