Omron CRT1 - 10-2008, Руководство по эксплуатации

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Analog Input Slave Units Section 6-4
6-4-3 Calculating the Conversion Cycle
The conversion cycle speed can be improved by setting the number of AD
conversion points, but will vary with the use of the math operations. Use the
following table and formula to calculate the conversion cycle time.
Formula AD conversion cycle time = AD base conversion time + (Additional time for
each function)
AD base conversion time: Cycle time when the math operation is not used at
all. The value for each conversion point from 1 to 4 is different.
Additional time for each function: The additional time that is required when
math operations are used.
The following table shows the AD base conversion times (unit: ms).
Note The CompoNet communications cycle is 4 ms.
The following table shows the additional time required for each function
(unit: ms).
Calculation Example When using three points, and applying scaling to the first and second inputs,
and the cumulative counter to the third input, the maximum AD conversion
cycle time can be obtained by using the following formula.
Formula: 3.21 + (0.055
×
2) + 0.035 = 3.355 ms
2 HD2 Hold Flag for
Input 2 The hold function is performed for Analog
Input 2 while this flag is ON. The hold func-
tion stops and the last value is held when the
flag goes OFF.
3 HD3 Hold Flag for
Input 3 The hold function is performed for Analog
Input 3 while this flag is ON. The hold func-
tion stops and the last value is held when the
flag goes OFF.
Bit Abbreviation Name Details
Time 1 point 2 points 3 points 4 points
Max 1.66 2.42 3.21 3.82
Min 0.68 0.81 1.47 2.03
Average 0.88 1.60 2.32 3.07
Σ
Math operation Additional time for each point
Moving average 0.045
Scaling 0.055
Peak/bottom hold 0.025
Top/valley hold 0.070
Comparator 0.065
Rate of change 0.030
Cumulative counter 0.035