5. SEQUENCE INSTRUCTIONS
5 − 27
MELSEC-A
Functions (1) Reverses the output status of the device, (D1), on the leading edge of the
output reverse command.
(2) Though (D2) is a dummy data, specify any device number indicated with the
mark for it. If a bit device is specified for (D2) , specify the digit with K1 to K4.
Specify any value since this digit specification value is a dummy data.
Device specified for (D2) can be used freely for other purposes.
(3) The CHK instruction is only executed in refresh mode.
(4) The output reverse command on/off period must be equal or greater than 1 scan
time.
Program Example CHK
The following program reverses the output status of Y10 when X9 is switched on.
X005
K4
CHK Y010 M1
X5 OFF
Y10 ON
OFF
ON
0
X009
CHK Y010 D0
• Coding
0 LD X009
1 CHK Y010 D0
6 END