HEIDENHAIN iTNC 530 Service Manual page 78

Possible If there is a difference (e.g., the voltage level is within the tolerance range but the logic state is
causes of error 0), this could have the following causes:
Checking the
PLC outputs


Assignment --> see "Connector Designation and Layout" on page 13 – 135
10 – 78
Defective input at the MC or the PLC expansion board
Defective cable or connector
Disturbance in the PLC bus
Note
It is not possible to measure PLC inputs directly at the handwheel or at the cable adapter
for the handwheel!
Note
If the test adapter (or the "Universal Measuring Adapter") by HEIDENHAIN is available, they
can be connected between the connectors X42 and X45 of the MC and the voltage level of
the input to be checked can be measured. --> see "Inspection, Measuring and Test
Equipment" on page 29 – 455
 Call TABLE function
 Display of the outputs
Regard the logic state of the output to be checked.
Measure the voltage and, if required, the current for the output to be checked, e.g.
At the terminals in the electrical cabinet where X41 is connected
Directly at the terminals of the machine operating panel
Directly at the terminals of the PL 4xxB input/output unit
Directly at the terminals of the EA module PLD 16-8
Note
An active output at the PLD 16-8 is indicated by a yellow LED!
A red LED at X4/pin1 indicates a short circuit at the output side of a PLD 16-8.
HEIDENHAIN Service Manual iTNC 530