Reserved Parameters

The retained band is where a value survives a power cut, which is why it is the obvious place to keep your own. Part of it is already occupied: the probing, tool-setting, warm-up and tool-change cycles that ship with the machine keep their settings there.

Overwriting one is silent. Nothing is reported and nothing alarms. The next tool change or measurement runs against your number instead of the machine’s.

Check the machine, not this page

Every reserved parameter ships with a name, and the PARAMETERS screen shows it beside the number:

520    TLM Setter X (machine)
521    TLM Setter Y (machine)

A number with a name is spoken for. A number with none is free. That rule stays true on a machine whose builder has added cycles of their own, which a printed list cannot.

What holds what

Band	Held by
500 to 505	the safe point, per axis
510 to 516	the auto-levelling grid: start, end, point counts and safe Z
520 to 527	the tool setter: where it is, and the feeds used against it
540	the work Z probe search travel
550 to 561	edge probing in X and Y: direction and travel
571 to 582	part probing: descent feed, clearances, search travels, capture feed
602	the tool break tolerance
610 to 615	the tool change position
620 to 625	the park position
630 to 633	the spindle warm-up stages and dwell
661 to 678	the backlash measuring cycles, probe and indicator
700 to 704, 719	the tool changer: heights, feeds and its mode
720 upward	the pocket table, see below

The pocket table grows

Each tool’s pocket takes four numbers starting at 720: pocket X, pocket Y, the engage Z, and a spare.

tool N   →   #[720 + (N-1) * 4]

Tool 1 is 720 to 722 and tool 4 is 732 to 734, so a rack of thirty-two tools reaches past 840. How far the band actually runs depends on how many pockets the machine has, which is why a number that is free on a small machine is not free on a large one.

Some of these are written by the machine

The backlash cycles report their results into 668 to 671 and 678, and the probing and auto-levelling cycles write their measurements back the same way. A value you store in one of those survives exactly until the next time that cycle runs.

Picking one for yourself

• Take a number with no name on the PARAMETERS screen, and stay clear of 720 upward.
• Give it a name there. That is what stops the next person, or you in a year, from taking it.
• Anything below 500 is a different band altogether: local variables, system variables and the tool table. See Macro Variables.

Where to go next

• Macro Variables: what each band of variables is for.
• Custom Macros: reading and writing them from a program.