My guess is clear was a relative term for the manual writers at Fanuc.
From what I could gather, the following parameters need to be set in conjunction with TLMB for a Series 15M:
6002.6 [QNI]
QNI Specifies the method used to set the tool offset number when measured tool offset input function B
(only for the Series 15–T and 15–TT) or tool length measurement function B (only for the Series 15–M)
is used.
0 : Select tool offset No. with cursor on MDI/CRT unit.
1 : Tool offset number is set by a signal from the machine.
I would be selecting option 0, select the offset on the offset screen.
6003.0 [TC2] & 6003.1 [TC3]
TC3 TC2 Meaning
0 0 Tool change position is the 1st reference point
0 1 Tool change position is the 2nd reference point
1 0 Tool change position is the 3rd reference point
Our particular machine uses G30 for the tool change position, so I would have to select 01.
6003.2 [TMA]
TMA Specifies the axis for which tool length is measured.
0 : Measure tool length along the Z–axis.
1 : Tool length can be measured for any axis.
Not sure which way to go yet, but most likely option 1.
6024
This parameter is used by function B for measuring tool length/workpiece origin.
For each axis, set the distance from the reference tool tip to the reference measurement surface (L in the figure
below) when the machine is at the machine origin.
Those are the parameters I found listed in the Fanuc Series 15/Fanuc Series 150 Operator's Manual (Appendixes) (B-61220E/05)
Now for the first step, I need to know what the switch in the following text (which was extracted from the Series 15 Operation Manual for Machining Center) does as far as signal input. Obviously the switch is an input to the PMC, probably a non-dedicated input. When the PMC receives this input, and the mode is in handle or jog (manual continuous feed), what signal does the PMC send to the CNC??
That is step one. My guess is there will be more. Once again, I apologize for the long winded post. I hope my thoughts came through clearly.
Ken