HEIDENHAIN TNC 415 (259 9x0) Service Manual - Manual (Page 148)

SERVICE MANUAL TNC 415B/425
Page 143
Issue: 20.08.95
19.6 Output "Control Ready for Operation" and
Acknowledgement for Test " Control Ready for
Operation "
Important functions are monitored by the TNC 415B/425 by way of a self-diagnosis system (electronic
assemblies such as micro-processor, EPROM, RAM, positioning systems, encoders etc.).
If an error is detected, a blinking error message in plain language is displayed in the dialogue line. As soon
as this error message is generated, the control opens the output "Control Ready for Operation".
The output "Control Ready for Operation" is available via:
Logic unit, connector X41 pin 34
PL 400, terminal strip X3 pin 10
PL 405, terminal strip X8 pin 16
PL 410, terminal strip X8 pin 16
By switching off the power switch or by pressing
END
this state can be cancelled, provided that the error
cause has been eliminated.
The output "Control Ready for Operation" is to switch off the +24V control voltage 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" each time the control is
switched on.
TNC 415B/425 features three monitoring systems (main processor, geometry processor and CLP processor)
which are also tested when the machine tool is switched on.
If the +24V at the input "Acknowledgement Control Ready for Operation" are missing during the test routine
after power-on, the error message " RELAY EXT. DC VOLTAGE MISSING" is displayed. If however, the
acknowledgement is switched off too late (or not at all) after the output has been switched off, the blinking
error message "EMERGENCY STOP DEFECTIVE" is generated. This error message is also displayed, if the
power supply of the PLC is missing (power supply of the PLC: see section 10).
If the control detects an error during the power-on test routine, a bridge can be inserted between the output
"Control Ready for Operation" and the input "Acknowledgement 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 PLC power supply, the defect is located in the logic unit.
If however, the error does not occur with the bridge being inserted, the defect is located in the interface.
Warning!
Do not forget to remove the bridge and to install the standard operating state after the test.
*
Observe the safety instructions!