HEIDENHAIN iTNC 530 Service Manual page 393

With the table for the PLC inputs you can check the condition of the MB keys (pressed or
not):
Figure: Observation of the NC-START button in the PLC table
July 2010
Switch on the machine.
Press the EMERGENCY STOP button.
Call the table with the PLC inputs. --> See "The TABLE function" on page 11 – 119.
Press the keys. --> The respective inputs must change to 1!
Exception: I147 = NC STOP, changes to 0 when actuated (broken wire interlock!)
Note
You can measure the voltage of the inputs, e.g., with a connected test adapter.
The logic state in the PLC-TABLE must be in agreement with the voltage level of each input!
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