Mitsubishi MELSEC-Q QD77MS, User Manual

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Chapter 14 Common Functions
[1] Operation for mark detection function
Operations done at mark detection are shown below.
• Calculations for the mark detection data are estimated at leading edge/trailing
edge of the mark detection signal.
However, when the specified number of detections mode is set, the current
number of mark detection counter is checked, and then it is judged whether to
execute the mark detection.
• When a mark detection data range is set, it is first confirmed whether the mark
detection data is within the range or not. Data outside the range are not
detected.
• The mark detection data is stored in the mark detection data storage area
according to the mark detection mode, and then the number of mark detection
counter is updated.
(1) Continuous detection mode
0 1 2
0 1
4: High speed input request
Mark detection signal
(Leading edge detection
setting)
Mark detection data value
Md.801 Mark detection data storage
area
Detected real current value Detected real current value
Real current value
(Continuous update)
Data outside range are not latched.
Confirmation of mark detection data range
(Upper/lower limit value setting: Valid)
Number of mark detection
counter Md.800
External command function
selection Pr.42
External command valid Cd.8
Set "1" before mark detection start.
"0" clear by setting "1" in " Cd.800 Number of mark detection clear request".
(2) Specified number of detection mode (Number of detections: 2)
0 1
0 1 2
Detection real current value (2nd)
Detection real current value (1st)
Real current value
(Continuous update)
Confirmation of mark detection data range
(Upper/lower limit value setting: Valid)
"0 clear" by "1" of " Number of mark detection clear reqest". Cd.800
4: High speed input request
Mark detection signal
(Leading edge detection
setting)
Mark detection data value
Md.801 Mark detection data storage
area (2nd area)
Number of mark detection
counter Md.800
External command function
selection Pr.42
External command valid Cd.8
Md.801 Mark detection data storage
area (1st area)
Set "1" before mark detection start.
Mark detection is not executed
because the number of mark
detections counter is already
2 (More than the specified
number of detections).