HEIDENHAIN TNC 306 Service Manual - Manual (Page 89)

SERVICE MANUAL TNC 306/360
Page 82
HEIDENHAIN Service
17.4 Output "Control Ready for Operation" and
Acknowledgement
for Test "Control Ready for Operation"
Important functions are monitored by the TNC 306/360 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.
By switching off the main switch or by pressing
END
, this state can be cancelled, if the
error cause has been eliminated.
The output "Control Ready for Operation" is to switch off the control voltage of +24V in the
machine tool interface. Since this function is an important safety function, the switch-off
function of the output "Control Ready for Operation" is tested via the input "Acknowledge-
ment Control Ready for Operation" every time the control is switched on.
The TNC 306/360 comprises a monitoring system that is tested when the machine tool is
switched on.
If the +24V at the input "Acknowledge 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 to
late or not switched off at all after switch-off of the output, the blinking error message
"EMERGENCY STOP DEFECTIVE" is displayed.
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.
*
Attention!
Do not forget to remove the bridge and to install the standard operating
state after the test!