Rigid Tapping Help

It's a 7i77 and I haven't made any changes to the wiring, so assuming it was set up properly when I brought it home, it should be.

Is there an easy way to test the index signal or would I need a scope?

Let's not assume.
You are telling us you are not reading an index pulse. Let's rule out the wiring. Check with the manual to see if the index wire goes to the correct physical pin on the board.

Fortunately I've taken plenty of pictures of the boards and wiring so I can answer this from work!

The index wires are connected as:
Out Z+ to pin 23 (IDX5)
Out Z- to pin 24 (/IDX5)

This is to "Encoder 5" on the 7i77

Can you try this: (from a command line when LinuxCNC is running)

halmeter signal spindle-index-enable
halcmd sets spindle-index-enable 1

and hand rotate the spindle a full turn, if spindle-index-enable never gets cleared, the hardware is not seeing the index pulse and the signals need to be checked.

A quick way to check differential signals is to measure across the pairs with a voltmeter (that is to check IDX5, measure between TB4 pins 23,24 (IDX5, /IDX5) in both states of index

PCW wrote:

Can you try this: (from a command line when LinuxCNC is running)

halmeter signal spindle-index-enable
halcmd sets spindle-index-enable 1

and hand rotate the spindle a full turn, if spindle-index-enable never gets cleared, the hardware is not seeing the index pulse and the signals need to be checked.

A quick way to check differential signals is to measure across the pairs with a voltmeter (that is to check IDX5, measure between TB4 pins 23,24 (IDX5, /IDX5) in both states of index

I'll give this a shot tomorrow, but....

I'm a linux moron - is that a command line within linuxCNC or just a linux command line?


What am I looking for when measuring pins 23/24? A change in voltage when index hits?

1. Just a linux command line

2. There should be from 2 to 5 V across pins 23 and 24 and the polarity should reverse when index is hit (that is, if you measured +3V across the pins when off index, you should read -3V when on index)

halmeter and halshow run fine directly from the command line...
(at least in this case where LinuxCNC is already running )

OK, so "halmeter signal spindle-index-enable" pops up the hal meter window
and "halcmd sets spindle-index-enable 1" doesn't appear to do anything.

The hal meter initially shows "true" when the window pops up and changes to "false" when I rotate the spindle by hand. It stays false after that.

Probing pins 23/24 I see ~2.5v and it doesn't change when I rotate the spindle slowly.

Is it safe to assume that my encoder is shot? I've been hesitant to throw another $90 at an encoder without some verification, but if this is it, I'll get one ordered.