This block is similar to the
Hold
block. The only difference is that simulated real-world effects are applied on the
clocked input signal u before transforming the signal to a continuous-time signal
with a zero-order hold. In particular:
- The output is delayed by a fraction of the clock period,
if parameter computationalDelay = true.
The delay is defined by shiftCounter/resolution*interval(),
where shiftCounter and resolution are Integer parameters and
interval() is the time duration from the previous to the current
clock tick. The maximal possible computational delay is one clock
duration, and therefore there is the restriction that
shiftCounter ≤ resolution.
- The output is limited, if parameter limited = true.
- The output is value discretized in the form of an Digital-Analog converter
with a defineable number of bits,
if parameters limited = true, and quantized = true.
Example
The following
example
samples a sine signal with an amplitude of 2.0 with a periodic clock of 20 ms period
and delays it for 2 sample periods.
The resulting signal is hold with the HoldWithDAeffects block. As a result, the clock of hold.u starts
ticking at 40 ms. The output hold.y of the block is a continuous-time signal that is present
from the start of the simulation. Before the first tick of the clock of hold.u, it is set
to 0.5 (= the value of parameter hold.y_start). Additionally,
the following effects are added to the hold block:
- The output is limited to +/- 1.9.
- A computational delay of half of a sample period (= 1/2*20 ms = 10 ms)
is defined.
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model |
simulation result |
Due to the limitation of the output signal, the values of hold.u ≥ 1.9
are limited to 1.9.
If the hold output is delayed by one sample period, then the previous(..) value of the
input is output, and the first tick is delayed by one sample period,
as shown by the
modified example
from above:
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model |
simulation result |
Note, the computational delay of one sample period is defined
by shiftCounter=1, resolution=1, as shown in the icon of the
hold block.
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