I noticed when recording some cues the whole fixtures soft button (next to the record selected) I had not noticed that before but was interested in what tit did, after some experimentation and looking in the manual I have not been able to come up with an answer. I am guessing it 'touches' all the parameters in the cue but I am unable to get it to do anything.
If I'm not mistaken the whole fixture function has never been implemented. Originally it was supposed to record every parameter of every fixture in the programmer. As you said in your post, by touching the fixture you achieve the same result.
If it is all fixtures that are already in the programmer just press "Next" + "Back" and after press "touch", if it is for all fixtures that are in the patch, press the group "ALL" and after press "Touch".
A new function like Pig + "touche" (pig + "suck") or Fixture + "touch" (Fixture + "Suck") to "touch" or "Suck" all fixtures in the programmer or all Fixtures in the patch could be useful.
The Whole Fixtures option does indeed remain unimplemented. Bug #380 (yes a three digit bug number) indicates that this feature needs to be implemented.
