11 – 136 HEIDENHAIN Service Manual iTNC 530
11.4 Non-Volatile PLC Markers and Words
Certain PLC markers and words are not deleted when the machine is switched off but remain
battery-buffered in the RAM of the control.
The non-volatile PLC memory area is displayed on the PLC main menu.
For example: When replacing controls this information from the process memory of the
control to be replaced are saved on the hard disk in order to load in into the process memory of
the new control at a later date.
For test purposes the non-volatile PLC memory can also be saved and loaded again.
Saving on
hard disk
8 Call the PLC mode. --> See “Calling the PLC mode” on page 11 – 115.
8 Scroll through the soft-key row.
8 Call the TABLE function.
8 Scroll through the soft-key row.
8 Press this soft key. --> A default area is displayed.
Figure: Save non-volatile PLC markers and words
The iTNC 530 enters the maximum defined area of the non-volatile PLC markes and words
(e.g., B0 ... B127, M0 ... M999) automatically.
This range can be changed after prior consultation with the machine manufacturer.
Note: Here the unit B (bytes) instead of W (words) is not an error --> A byte is the smallest
subset of a word.