Mitsubishi Electric MELSEC-Q/L Programming Manual page 421

■DSER
• Searches n points from the device designated by (S2) in 32-bit units (2  n points in 16-bit units) regarding 32-bit data of the
device designated by (S1) +1 and (S1) as a keyword. Then, the number of matches with the keyword is stored at the device
designated by (D)+1, and the first matched device number (in the relative number from (S2)) is stored at the device
designated by (D).
Head number to be
searched
Search data
5678901
S 1
+1. S 1
S2
S2
S2
Relative value
+(n-3),
S2
S2 +(n-1),
• No processing is conducted if n is 0 or a negative value.
• If no matches are found in the search, the devices designated at (D) and (D)+1 become "0".
If the data to be searched using the SER/DSER instruction is sorted in the ascending order, searches can be
accelerated by the use of the binary search method, which is activated by turning SM702
However, correct search results are not obtained if SM702 is turned ON when the data to be searched is not
sorted in the ascending order.
*1 SM702 is the special relay for setting the search method.
• SM702 OFF: Sequential search method (linear search method)
(Comparison with the search data starts from the beginning of the data to be searched.)
• SM702 ON: Binary search method
(Obtains the center value of the sorted array and decides if the obtained value is larger or smaller than the search value, then, chooses the area for search
between the larger and smaller value divisions. By repeating this process, the area for search is narrowed down.)
Search data Data to be searched
500
200
300
Search range
400
500
Operation error
• In any of the following cases, an operation error occurs, the error flag (SM0) turns ON, and an error code is stored into SD0.
Error Error details
code
4101 The range of n exceeds that of the device specified in (S2)
The device range specified in (D) exceeds the range of the corresponding
device.
5678901
5678901
+1, 5678901
S2
123456
+3, S2 +2
-1
+5, S2
5678901
+(n-4)
S2
0
+(n-2)
S2
5678901
Search order
Data to be searched
100
Compared with the
search data
Search range
600
700
Match data
Search results
D
Search range
(2 n points)
+1
D
Data to be searched
100
200
300
400
500 Search range
Compared with the
600
search data
700
Q00J/ QnH
Q00/
Q01
 
 
1 Position of match
2 Number of matches
*1
ON.
100
200
300
400
500 Compared with the
search data
600
700
QnPH QnPRH QnU
  
  
7 APPLICATION INSTRUCTIONS
7.5 Data Processing Instructions
7
LCPU


419