Checking The Potentiometers - HEIDENHAIN iTNC 530 Service Manual

22.5 Checking the Potentiometers

You can use the table for the PLC words to find out, whether the control receives the
Potentiometer
potentiometer signal.
values in the
PLC-TABLE
The potentiometer setting is shown in the following PLC words:
Proceed as follows:
With the integrated oscilloscope you can record the states of PLC words as well.
Potentiometer
The advantage of this method is that possible wiper interruptions of the potentiometers can be
values in
recognized better than in the PLC TABLE.
the integrated
oscilloscope
Proceed as follows:
July 2010
W492 (=S override)
W494 (= F override)
Switch on the machine.
Press the EMERGENCY STOP button.
Call the table with the PLC words. --> See "The TABLE function" on page 11 – 119.
Place the cursor on W492 or W494 (e.g., GOTO 492).
Select the decimal display (soft key).
Turn the potentiometer to be examined.
Check if the display can be changed from 0 to 15000 (with nonlinear characteristic curve) or
0 to 150 (with linear characteristic curve).
The characteristic curve is defined in MP 7620 bit 3.
Switch on the machine.
Press the EMERGENCY STOP key.
Call the oscilloscope. --> See "Integrated Oscilloscope" on page 10 – 99.
Make the following settings:
Start the recording.
Turn the potentiometer to be examined.
Stop recording and adjust the signals.
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