Mitsubishi MELSEC-Q QD77MS, Руководство пользователя

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Chapter 14 Common Functions
14.9 Mark detection function
Any data can be latched at the input timing of the mark detection signal (DI1 to DI4).
Also, only data within a specific range can be latched by specifying the data detection
range.
The following three modes are available for execution of mark detection.
1) Continuous detection mode
The latched data is always stored to the first of mark detection data storage area at
mark detection.
Storage area 1
Mark detection data
storage area
Mark detection signal
2) Specified number of detections mode
The latched data from a specified number of detections is stored.
The detected position for a specified number of detections can be collected when
the mark detection signal is continuously input at high speed.
Example) Number of detections: 3
The 3rd detection
Mark detection data
storage area
Mark detection signal
The 4th detection
and later are ignored.
Storage area 1
Storage area 2
Storage area 3
Storage area 4
3) Ring buffer mode
The latched data is stored in a ring buffer for a specified number of detections.
The latched data is always stored at mark detection.
Example) Number of detections: 4
Mark detection data
storage area
Mark detection signal
The 4th detection
The 5th detection
replaces the previous
first detection.
Storage area 1
Storage area 2
Storage area 3
Storage area 4