idea about identifying pallets with touch probe on Fanuc 21-M control

I'm posting this in CNC section, since I think the question is more CNC control related rather than automation/robotics, here goes:

Would the following logic be doable on a Fanuc 21-M control, reason for asking is that we haven't bought the machine yet, but the one that would fit the purpose and budget is an early 2000s Chiron FZ 08 W, they seem to come with this Fanuc control, and if this is doable on it, I can go ahead and buy one to push the project further along.

Description:
1) a mini pallet with parts is placed on the machine table, fixed via Zero point mounting system
2) besides the parts, there is an "ID" block mounted on this plate, every pallet will have this ID block at the same place, they might come in sizes (X axis) 10mm/12mm/14mm etc.
3) The main program on the control would first probe this block in X axis and do something like this:
#X=(probe measurement of the right)-(probe measurement on the left)
4) the main program then would call another program with the name stored in the X variable

The idea here is that the pallets would loaded from racks by a robot arm (KUKA 761 will be used if that matters), the VMC then identifies which type of part is loaded and executes the machining program, some pallets may have 5 parts on them, some 20, and there might be 20 pallets of 1st type, 10 of the second and 10 of 3rd type all ran overnight unattended, that is the current idea.

For safety the "sub" programs would still probe the parts on the pallets to make sure they are seated properly etc, but the main "feature" would be the IDing of the pallet by probing the "ID" block on each pallet and calling specific machining program to be executed.

Full disclosure - I have no experience programming Fanuc controls, I have taught myself to use older Haidenhain controls in conversational mode (TNC155 and 355), can do basic CAM work, I know my way around electronics, IC programming, can write an app for a phone or a piece of software on a PC, but I only glanced over the G code basics so far, and from what I've gathered so far there are numerous versions of controls, and all sorts of different options on them that may allow or prevent doing what I described above, I just need someone with experience to tell me that I'm digging in the right direction, or pointer/keywords to use to search the forum to solve my problem, or even look for a machine with a different control.

The 21 is more than capable of doing what you suggest.

But let me just throw another idea that might lead you to possibly a different control, depending on what it is you are running.

We recently got a 21mb controlled machine. It came with 32KB of memory on it. Yeah, only roughly 32000 bytes.

Now, it looks like that's what they come with as standard as far as I can tell. But you can upgrade them.

Yet, it appears that you can only get up to 256KB on this control (please, someone correct me if I am wrong. I would love more memory available to me!!!)

You will want to figure out how much program space you need. If doing a lot of milling, you would likely need more memory (if space is low), because I don't think you'd want to try drip feeding with "random" pallets with different parts/programs on them.

Newer and different controls can have more memory in them, you MIGHT want to consider that. Even a 16/18 machine can have a lot more memory (2mb max according to memex). 16m/18m controls are actually better than a 21. go figure...

Looks like 16i/18i/21i are also upgradable to 2mb (might be more, quickly looked on google). Also, on the iB series controls, you can (usually, when supplied) read programs off of a cheap PCMCIA flash card (16iA/18iA/21iA card readers require an expensive SRAM card which is also expensive to get a usb card reader for. I suggest staying away from the older iA controls)


Summary: make sure the machine you get has enough memory, or at least can be upgraded to enough. do not fight program storage issues!!!