HEIDENHAIN iTNC 530 Service Manual page 275

The green LEDs indicate the correct supply:
LED display
The corresponding PLC outputs do not function. Depending on the PLC program of the machine
Error
manufacturer, PLC error messages are displayed.
Functional check
If this is not the case.
July 2010
Note
Monitoring the PLC outputs --> See "The TABLE function" on page 11 – 119.
Observe, whether the green LEDs on X6 pin 9 and pin 10 of the PLD16-8 input/output modules
are lit.
Observe, whether the green LED POWER ON on the basic module PLB 510 is lit.
Measure whether the 24 V supply voltages are available as indicated above.
Note
If the LEDs are not lit, despite available power supply, the basic module PLB 510 or the
corresponding I/O module PLD 16-8 is probably defective.
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