Mitsubishi 00JCPU User Manual page 394

3) LED indication
When all of the annunciator numbers in SD64 to SD79 turn off, the LED that was turned on by turn-on of the
annunciator will turn off. (
If the LEDR instruction is executed while the annunciator is on and at the same time the operation continuation error that has
higher priority (
error. Because of this, the annunciator is not turned off by execution of the LEDR instruction.
To turn off the annunciator with the LEDR instruction, remove the error whose priority is higher than that of the annunciator.
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(5)(b) in this section)
Section 6.21.2) than the annunciator has occurred, the LEDR instruction clears the higher priority