309
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
Summary of Contents for CRT1 - 10-2008
Page 2: ...CRT1 Series CompoNet Slave Units and Repeater Unit Operation Manual Revised October 2008...
Page 3: ...iv...
Page 5: ...vi...
Page 9: ...x...
Page 15: ...xvi...
Page 23: ...xxiv Conformance to EC Directives 6...
Page 51: ...28 Slave Unit Models Section 1 2...
Page 123: ...100 Connecting External I O for Slave Units Section 3 6...
Page 365: ...342 Temperature Input Units Section 7 5...
Page 381: ...358 Expansion Unit Specifications Section 8 2...
Page 418: ...395 Repeater Unit Section 10 2 Dimensions 42 3 50 3 1 27 5 95 mm...
Page 419: ...396 Repeater Unit Section 10 2...
Page 424: ...401 CX Integrator Section 11 1...
Page 575: ...552 Current Consumption Summary Appendix D 552...
Page 581: ...558 Index...
Page 583: ...560 Revision History...