When you power up a CNC machine tool, certain modes are initialized – that is – automatically selected. With many machines, for example, the machine will come on in the rapid (G00) mode. If the first motion command after power up is given without a G code to specify the motion type (G00, G01, G02, G03), the machine will move in the way the motion type has been initialized – rapid motion in our example.
It is important to know that certain initialized modes are set by parameter – and they can be changed. In the case of the motion type initialization, you may not want the machine initializing in the rapid mode, especially if your people make a lot of MDI commands. You may, instead, want the machine initializing in the linear interpolation (G01) mode. This will be safer – if a person forgets to include a motion type in the first MDI command (right after power up), the machine will not rapid.
For a 16 series control (16T or 16M), bit number zero (right-most bit) of parameter number 3402 controls which of G00 or G01 will be initialized after power up. Though the documentation in my manual was not specific, if I remember correctly, when this bit is set to a zero (0), rapid mode is initialized. If it is set to a one (1), linear interpolation mode is initialized.
You must check in your machine documentation (or test) to confirm this. And of course, each control model has a different set of parameter numbers – and you must find the appropriate one (look for the notes just after the list of G codes in your operation manual) for your particular control/s.
Again, other initialized states can also be adjusted in this manner. The initialized state of absolute mode and incremental mode (G90 and G91), plane selection (G17, G18, and G19), rapid and initial plane with canned cycles (G98 and G99), and stored stroke limit (G22 and G23) are among the functions you can control in this manner.
One more note. With most machines, the RESET button will return the machine to its initialized states (another parameter controls whether or not this will happen). This means that when you press the RESET button, the machine will return to its initialized state.