HEIDENHAIN TNC 407 (243 020) Service Manual - Manual (Page 101)

D-83292 31-O
SERVICE MANUAL TNC
Issue:
01.09.1995
Page 83
17.4 Output “Control Ready for Operation” and
Acknowledgement for Test “Control Ready for Operation”
Important functions are monitored by the TNC by way of a self-diagnosis system (electronic
assemblies such as the micro-processor, the ROM, read/write memory, positioning systems, encoders etc.)
If an error is detected, a blinking error message is displayed in plain language in the dialog line. As soon as
this error is displayed, the output “Control Ready for Operation” becomes inactive.
The output “Control Ready for Operation” is available via the connectors of the LE and on the terminal
X3 /pin 10 of the I/O board PL 400. If the error cause has been eliminated, this state can be cancelled by
switching off the main switch or pressing
The output “Control Ready for Operation” is to switch off the control voltage of in the machine tool
interface. Since this is an important safety function, the switch-off function of the output “Control Ready
for Operation” is tested via the input “Acknowledgement Control Ready for Operation” every time the
control is switched on.
The TNC 407 features a monitoring function that is tested when the machine tool is switched on.
The TNC 415 comprises 3 monitoring systems (main processor, geometry processor and CLP processor)
that are also tested when the machine tool is switched on.
If the at the input “Acknowledgement Control Ready for Operation” are missing during the test routine
when the control is switched on, the error message “RELAY EXT. DC VOLTAGE MISSING” is generated.
If however, the acknowledgement is switched off too late not switched off at all) after switch-off of the
output, the blinking error message “EMERGENCY STOP DEFECTIVE” is displayed. This error message is
also generated, if the power supply of the PLC part is missing (power supply of the PLC part: see section 8.6).
If the control detects an error during the switch-on test routine, a bridge can be inserted between the outputs
“Control Ready for Operation” and “Acknowledge Control Ready for Operation” (disconnect the wires) in order
to determine whether the defect is due to the control or to the interface. If the error is still present after
inserting the bridge and with correct power supply of the PLC part, the defect is located in the logic unit.
If however, the error does not occur any longer after the bridge has been inserted, the interface is defective.
Note:
Do not forget to remove the bridge and to install the standard operating state after the test