HEIDENHAIN iTNC 530 HSCI Technical Manual page 1527

July 2013
After the SHUTDOWN soft key has been pressed, the PLC program can delay
or prevent the display of the pop-up window (shutdown: yes/no). The
message "The TNC will be shut down and machine functions will be
performed" in the operating modes window indicates this condition. An
appropriate user guidance must have been programmed by using the available
tools, such as dialog texts, pop-up windows, vertical soft key, etc., in order to
inform the user about concluding operating steps that may be necessary.
The possibilities of configuring a shutdown (MP4040 and the subsequent
functions) specified below can continue to be used, because these settings do
not become effective until the prompt "Do you really want to switch off?" has
been acknowledged.
M4195

The marker M4195 is set when the SHUTDOWN soft key is pressed (= 1).
The PLC program can prevent the control from shutting down by resetting
the marker in the next PLC cycle. In this phase (M4195 = 0), the text "The
TNC will be shut down and machine functions will be performed" is
displayed in the operating modes window and the PLC program can execute
specific actions before shutting down the control. The TNC remains in this
condition until the marker M4195 is set again.
M4197

If the PLC actions cannot be concluded, the PLC can cancel shutdown of the
control by setting marker M4197 = 1. Then the TNC returns to its original
mode of operation and the two markers also return to their initial state.
With MP4043 you can delay the shutdown of the control (after pressing the
SHUTDOWN soft key) to enable the PLC to execute final actions.
When you press the SHUTDOWN soft key, the control starts shutting down,
PLC marker M4179 is set and the delay time entered in MP4043 starts to
elapse. The PLC program can execute final actions during the delay time. If the
PLC marker M4179 is reset by the PLC program, the SHUTDOWN process
will be continued before the time set in MP4043 has elapsed.
The SHUTDOWN process is automatically continued at the latest after the
expiration of the time in MP4043.
If the following conditions apply, however, it cannot be guaranteed that final
PLC actions (e.g. data backup of non-volatile memory ranges of the PLC) are
executed:
If no PLC program is active at the time the control is shut down,

(e.g. PLC run time error has occurred, power interruption status), the
shutdown time is not delayed.
If a PLC run time error occurs during shutdown, the delay is canceled.

MP4043 Delay during shutdown for the PLC to execute final actions
Input: 1 to 1000 [s]
0 = No delay
M4195 Press the SHUTDOWN soft key
M4197 Cancel the shutdown of the control
8.9 PLC inputs/outputs
Set Reset
NC NC
PLC NC
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