Chapter 6 Applied Instructions Note: SM685=ON (the floating point number operation) works for the 32-bit instruction only. 3. S 1 is the data source. S 2 is the number of multi-point areas and the value should be between 2 and 50. If the value exceeds the range, the instruction will be executed automatically at the minimum value or maximum value. S 3 is a setting value for comparison in a multi-point area. S 4 is a conversion reference value that a multi-point area comparison value corresponds to, e.g. the number of areas, S 2 is 10. Then S 3 ~ S 3 +9 are comparison values in 10 areas. S 4 ~ S 4 +9 are 10 corresponding conversion reference values. 4.
The comparison order for multi-point areas is 0, 1, 2 … S 2 –1. The comparison rule is S 1 >= S 3 +0 and S 1 S 3 +1. If S 1 value does not belong to an area, the comparison will move on to the next area. For example, S 1 >= S 3 +1 and S 1 S 3 +2, the comparison keeps going until the number of comparison times reaches S 2 – 1. 5. The instruction compares areas in the order from small to large. Please design the value comparison of S 3 area in the order from small to large as well. 6. See the figure below for the conversion of multi-point area values. (Set the number of areas, S 2 to 4.) S 4 6_ S 4 +0 D S 4 +1 S 4 +3 S 4 +2 S 3 S 3 +0 S 3 +1 S 3 +2 S 3 +3 S 1 7.
If S 1 value is between S 3 +0 and S 3 +1, the conversion formula: D = ﹝ ( S 1 – S 3 +0) x ( S 4 +1 – S 4 +0 ) / ( S 3 +1 – S 3 +0 ) ﹞ + S 4 +0. 8. If S 1 value does not belong to any specified area, the execution result in D is explained as below. If S 1 value > the last specified area, D will store the last conversion reference value of S4, e.g. if S 1 value > S 3 +3 value in the figure above, D = S 4 +3. 6-119 32-bit instruction 16-bit Constant instruction SM685 ON SM685 OFF K X 16# X F X X