SEQ – Sequencer - Przełącznik urządzeń pracujących w kaskadzie
Wejście, AI typu Real, % Wyjście, AO typu Integer
Stages REAL Liczba procesów wyjsciowych (1 to 16).
Rotation BINARY Zdefiniowanie rotacji procesów lub jej braku
Period INTEGER Opóźnienie jednoczesnej aktywacji procesów (milisek.) Hysteresis REAL Wartość histerezy (%).
This block is used to start N of M stages, where M is the total number of output stages as defined by the parameter Stages (up to a maximum of 16) and N is the integer part of the result of the following calculation:
N=(M+1)*Input/100
where Input is a value between 0% and 100%. The M stages are represented by the first M bits of the integer block output value. The first N of these bits will be true (1) and the rest false (0).
Example: If Stages is 4, and neither Hysteresis nor Rotation is used, stage one will be started (Output = 1; 0001) at 20% Input signal, stage two (Output = 3; 0011) at 40%, stage three (Output = 7; 0111) at 60% and stage four (Output = 15; 1111) at 80%. Note that TAC Menta uses two-complement representation of signed integers, i.e. the output signal for starting 16 stages will be -1 (1111111111111111).
If the parameter Hysteresis is zero, the previous formula will give the number of stages activated as a function of the input signal. If Hysteresis has a non-zero value, a hysteresis loop will exist to the left or to the right (depending if Hysteresis is a negative or a positive number) of the points calculated in the prior equation. In this case, the activation values of the stages will be displaced with respect to the deactivation values. For example, if we define a 4 stage sequencer, the stages started according to the previous formula will be one stage at 20%, two stages at 40%, three stages at 60% and four stages at 80%. If a positive hysteresis is defined, e.g. equal to 10, the activation of the stages will be displaced to the right by 10%, that is the activation of the stages will be produced at 30%, 50%, 70% and 90%, but the deactivation is maintained at the previous values.
On the other hand, if the hysteresis were negative, for example -15%, the deactivation would be displaced to the left and therefore, the stages would activate at 20%, 40%, 60% and 80% and be deactivated at 5%, 25%, 45% and 65%.
The parameter Period is used to prevent two or more stages from being activated simultaneously. If the value is non-zero, the stages will always be activated sequentially with an interval equal to Period (milliseconds), even though the input were to vary sharply, obliging the simultaneous activation of the stages. However, if this value is zero, the stages may be activated simultaneously.
The parameter Rotation determines if the active stages should rotate or not. The difference between Rotation = 1 (with rotation) and Rotation = 0 (without rotation) is that in the first case the stages will deactivate in the same order in which they were activated, that is the stage which has been active the longest time will always be deactivated first, while in the second case, the deactivation order is the opposite of the activation order. When the sequencer is defined with rotation, it may be assumed that the time which each stage remains active will in the long term be approximately the same for all stages.
