Yokogawa DAQWORX - Manual (Page 66)

2-36 IM WX103-01E
• Handling of NaN values
• In the case of a TLOG function (tlogmax, tlogmin, tlogpp, tlogsum, and tlogave)
If NAN exists in the channel values, it is handled as though the value did not exist.
• In the case of the IsNan() function
This function can determine whether the value is NaN.
• In the case of min, max, sum, ave, and pp functions
NaN values are discarded.
• In the case of &&, ||, ^^, and ! operators
NaN values are considered true.
• For all other computations
Computation is performed taking NaN as a value. Thus, NaN is returned as the
computed result.
• The numeric value display on the Monitor screen displays INVALID.
• Handling when the value of a measurement channel is ±Over (exceeding the upper
and lower limits of the measurement range)
If the measured value used in the reference function or TLOG function is ±Over,
computation continues in one of two ways. Select the handling method using the
Calculate +Over/-Over as the MAX/MIN value of a range check box.
• Continue the computation as ±Over.
• Continue the calculation by setting ±Over to the maximum or minimum value of the
measurement range of the specified channel.
Use the following values as the maximum and minimum value of the measurement
range.
• DC voltage: ±10% of the range
However, 0/+63.000 mV for 60-mV (HQ) range and 0/+6.3000 V for 6-V (HQ)
range.
Example: 6 V range
+OVER: +6.6 V
–OVER: –6.6 V
• Temperature: ±10°C of the rated measurement range
However, 0 K and 10 K for KpVsAu7Fe and J263B.
• Linear scaling: Maximum and minimum values of the scale corresponding to
±10% of the measurement span
However, ±32000 when the scale value exceeds ±32000.
Example 1: When the measurement span is set to ±1 V and the scale is set to
±10000 at 2 V range
+OVER: +22000
–OVER: –22000
Example 2: When the measurement span is set to ±1 V and the scale is set to
±30000 at 2 V range
+OVER: +32000
–OVER: –32000
To suppress ±Over from occurring in the computation, use the limit function.
• Alarms for computation using the Alarm() function
The alarm corresponding to the current value is used for the alarm of a measurement
channel.
The alarm corresponding to the current value is also used for the alarm of a
computation channel. However, for computation channels that have not yet computed
the current value, the alarm corresponding to the previous value is used.
2.5 Settng Computatons (Settng the Computaton Channels)