Yokogawa DAQWORX Manual do Utilizador Página 65

  • Descarregar
  • Adicionar aos meus manuais
  • Imprimir
Vista de página 64
2-35
IM WX103-01E
1
2
3
4
5
Index
Logger
Notes on Computation
The equation is not case sensitive. The exception is tag numbers specied on the
Channel setup screen.
The precision and range of computed values are the same as data in single-precision
oating point format.
The sampling interval of the computed channel is 100 ms to 10 min.
Measured values used in computations
The measured value with the closest time is used among the m
easured values
existing at the time of computation. Resampling of the measured value or interpolation
are not performed while computation is being executed.
Example 1:
If the measured values indicated by
and exist and computation indicated by
is performed, the measured value indicated by
on each channel is used. If the
measured value does not exist such as in Ch 5, NaN is used as the measured value.
Ch 1:
Ch 2:
Ch 3:
Ch 4:
Ch 5:
Math:
: Data at time t
: Newest data
: Oldest data
: NaN
t
: Data near tie t
Measured value used in
the computation of
Example 2:
If the disconnection (disconnected after
) is detected, NaN is used as the measured
value of Ch 3.
Ch 1:
Ch 2:
Ch 3:
Ch 4:
Ch 5:
Math:
: Data at time t
: NaN
: Oldest data
: NaN
t
: Data near tie t
Measured value used in
the computation of
Alarm values used in computations
Basically handled the same as measured values except the behavior differs in the
following two cases.
When the alarm value does not exist (Ch 5 in example 1 above)
Always returns 0 (no alarm).
When the communication is cut of
f (Ch 3 in example 2 above)
Always returns the most-recent value.
Syntax error and execution error
Syntax error
Equations containing items that are inappropriate are indicated in peach when the
equation is being entered. If monitoring is started without correcting the equation,
they are ignored.
Execution error
Execution errors are detected after starting the execution. Below are the two cases.
NaN is returned as the result in either case.
When the reference destination does not exist when monitoring is started
When the computed result is undened.
2.5 Setting Computations (Setting the Computation Channels)
Vista de página 64
1 2 ... 60 61 62 63 64 65 66 67 68 69 70 ... 162 163

Comentários a estes Manuais

Sem comentários