2 skip function, Melsec-q, 1] control details – MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D User Manual
Page 539: 2] precautions during control
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MELSEC-Q
12 CONTROL SUB FUNCTIONS
12.7.2 Skip function
The "skip function" is used to stop (deceleration stop) the control of the positioning
data being executed at the time of the skip signal input, and execute the next
positioning data.
A skip is executed by a skip command (
Cd.37
Skip command) or external command
signal.
The "skip function" can be used during control in which positioning data is used.
The details shown below explain about the "skip function".
[1] Control details
[2] Precautions during control
[3] Setting the skip function from the PLC CPU
[4] Setting the skip function using an external command signal
[1] Control details
The following drawing shows the skip function operation.
BUSYsignal
V
Deceleration by
skip signal
Start of the
next positioning
ON
OFF
OFF
OFF
OFF
ON
ON
ON
Positioning
Positioning start signal
Positioning complete signal
Skip signal
t
[XC, XD, XE, XF]
[Y10, Y11, Y12, Y13]
[X14, X15, X16, X17]
Fig. 12.37 Operation when a skip signal is input during positioning control
[2] Precautions during control
(1) If the skip signal is turned ON at the last of an operation, a deceleration stop
will occur and the operation will be terminated.
(2) When a control is skipped (when the skip signal is turned ON during a
control), the positioning complete signals (X14, X15, X16, X17) will not turn
ON.
(3) When the skip signal is turned ON during the dwell time, the remaining dwell
time will be ignored, and the next positioning data will be executed.
(4) When a control is skipped during interpolation control, the reference axis
skip signal is turned ON. When the reference axis skip signal is turned ON,
a deceleration stop will be carried out for every axis, and the next reference
axis positioning data will be executed.
(5) The M code ON signals (X4, X5, X6, X7) will not turn ON when the M code
output is set to the AFTER mode (when "1: AFTER mode" is set in "
Pr.18
M code ON signal output timing").
(In this case, the M code will not be stored in "
Md.25
Valid M code".)
(6) The skip cannot be carried out by the speed-position and position-speed
switching control. It is processed in the same manner as in the speed
control.