11 Tool Function
11 Tool Function
11.1 Tool Select Command (Code T)
With a number of max. four digits written at address T, the NC will give a code to the PLC. When a movement command and a tool number (T) are programmed in a given block, function T will be issued during or after the motion command. The machine tool builder will define the way of execution.
11.2 Program Format for Tool Number Programming
There are basically two different ways of making reference to a tool change in the part program. They depend on the configuration of the
Case A
A tool change can be accomplished on the machine manually or by means of a turret type tool changer. Now, with reference made to code T:
–in the case of manual tool change, the number of tool to be used appears on the display; it has to be clamped in the spindle manually. Afterwards, the machining will be resumed upon a start;
–in the case of a turret type tool changer, the new tool will be put to position of use automatically under the action of code T.
Thus a reference to the tool number will evoke an immediate change in the block which T has been specified in.
Case B
A tool change needs some preparations on the machine. Its steps:
–The tool to be employed has to be found in the magazine. Now reference to address T in the part program will bring the appropriate tool in change position. This operation is carried out in the background, simultaneously with the machining.
–The slides (or only one of them) have to be sent to the change positions.
–The tool change is carried out by function M06 in the program. The control will wait for the execution of the tool change until tool T (under preparation) is brought to change position. As a result, the new tool will be placed in the spindle. Henceforth cutting may be resumed.
–The old tool is replaced in the tool magazine. This activity is performed in the background, simultaneously with cutting.
–The search is commenced for the new tool in the magazine.
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