Switch relay in a defined x position

Yes, it seems to have gone to the right place.

The function name is probably downdraft.0

(and it might be simpler to use one of the built-in modules, terse[1] documentation aside.)

[1] Terse to a fault, I agree

Actually, I think my hal example uses names=ddraft
and has a typo
try
addf ddraft servo-thread
 

Success message it works great
You are the greatest guys thank you!

There was still some grumbling in one place but that could be fixed quickly.

Here again for the sake of completeness.
The following must be entered in the hal:

loadrt downdraft name=ddraft
addf ddraft servo-thread
net position axis.x.pos-cmd. => ddraft.position
net ddraft-trigger ddraft.trigger
setp ddraft cutover 800
setp ddraft cutoff 1200

great work, glad it works for you.
Custom components are so simple yet so few know they can be written

andypugh wrote:

Isn't this something that the built-on "comp" or "wcomp" components can do?

linuxcnc.org/docs/2.8/html/man/man9/comp.9.html
linuxcnc.org/docs/2.8/html/man/man9/wcomp.9.html
 

Do you know of a code snippet anywhere as an example of how we might use comp or wcomp to trigger pins based on X axis position? I have built a 5 x 10 table and am building a zoned downdraft system for it with five zones. I want one zone open at a time based on position of the X axis; and a time delay so that open zones do not close for a few seconds after X has moved out of  a zone. I am not concerned with the position of Y.

RodW and another member have such a system in use, so it can be done.
How, i'll leave that to them to explain.
Found one of the topics:
forum.linuxcnc.org/plasma-laser/40517-do...gn-questions?start=0