HEIDENHAIN iTNC 530 Service Manual page 123

Checking the
PLC outputs
Assignment --> See "Connector Designation and Layout" on page 27 – 447.
Conclusion The logic states in the PLC table must be in agreement with the voltage levels for each
output. --> See "Specifications" on page 11 – 147.
Meaning of the
LED
LEDs on the
PLD 16-8 Red LED at X4, pin 1
Yellow LEDs at X4, X5 and X6
Green LEDs at X6, pin 9 and pin 10
a. In case of a short circuit of an output, the output voltage is reset.
July 2010
You have called TABLE.
Press the OUTPUT soft key.
Place the cursor on the output to be examined (e.g. GOTO O32 ENTER).
Observe the logical state of the output to be checked.
Check whether the connected actor (relay, etc.) has triggered or whether the connected
device operates.
Measure the 24-V supply voltage DC-link voltage (electrical cabinet voltage).
Measure the voltage for the output to be checked, e.g.:
At the terminal strips in the electrical cabinet where the PLC outputs are connected.
Directly at relay terminals, ect.
At the terminals (X4) of the machine operating panel.
At the terminals (X7, X8) of the PL 4xxB input/output unit.
At the terminals (X6) of the input/output module PLD 16-8.
Note
The output voltage for the "1" signal must not be more than 3 V below the measured 24 V
supply voltage (e.g., 22.7 V - 3 V = 19.7 V).
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.
Note
It is not possible to measure PLC outputs directly at the handwheel or at the cable adapter
for the handwheel!
Note
If the HEIDENHAIN test adapter is available, you can connect it between the connectors
X41 and X46 of the MC to measure the voltage level of the input to be checked. --> See
"Measuring circuit with test adapter for PLC inputs and outputs on the MC" on page 11 –
124.
The short-circuit monitoring remains in place. It can be reset with the manufacturer's
PLC program or by switching the machine on and off.
In order to recognize a short circuit, a current of 20 A must be able to flow for approx. 3 ms.
If this is not the case (e.g. the 24-V supply limits the current sooner), the short-circuit
monitoring might not become effective.
Status Meaning
Continuously on Short circuit of the outputs
On Inputs/outputs set
On 24 V power supply of the outputs
a
11 – 123