Mitsubishi Electric MELSEC-Q/L - Page 421

7 APPLICATION INSTRUCTIONS
7.5 Data Processing Instructions
419
7
■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).
• 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
*1
ON.
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.
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.
• 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.)
Error
code
Error details Q00J/
Q00/
Q01
QnH QnPH QnPRH QnU LCPU
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.

D
S2
D
S2
S2
S2
S2
1
2
Position of match
Number of matches
Search range
Search results
Match data
Head number to be
searched
5678901
Search data
+1.
-1
5678901
5678901
0
5678901
5678901
123456
5678901
S1
S
1
S2
S2
S2
S2
S2
Relative value
(2 n points)
+1
+1,
+3,
+5,
+2
+(n-3),
+(n-1),
+(n-4)
+(n-2)
Data to be searched
500
400
600
200
300
100
700
Data to be searched
500
400
600
200
300
100
700
Data to be searched
500
400
600
200
300
100
700
500
Search data
Search order
Search range
Compared with the
search data
Search range
Compared with the
search data
Search range
Compared with the
search data