Playing with Asian DRO's and logic analysers

[WJH]

I have an old Meister S2000 2 axis DRO on my milling machine that was made in Singapore, and it uses the round DIN style plugs... I've always wanted to add the 3rd axis for Z, which meant a new DRO head. The plan is to take the old head and put it on my lathe. I ordered my new head from China directly from Alibabba, and it is made by Ditron. It was 120$ + 50$ shipping, and I am blown away by how good the quality is!
Anyhow, I also ordered a glass scale by Ditron from an importer in California.
Now here is the dilemma... The new glass scale uses a DB9 connector, and the wiring is completely different. So how does one figure out which wire is which for converting the older scales with Din7 connectors to new DB9's for the new head? Well, easiest would be a spec sheet but my old DRO is an information black hole...
Simple, use a logic analyzer!! An oscilloscope also would work...
Logic analyzers, as the name would suggest, analyze logic, and specifically in our case, TTL level logic which is 0v for a 0, and +5v for a 1.. Don't hook one of these things up to more than 5v... As luck would have it, these Chinese glass scaled DRO's use TTL logic, and the quadrature output is easy to see!

The black wire is 0v
The red wire is 5v
The yellow wire is R, which is a tick it sends out I think at the half way travel mark, as you can see
The green wire is A (or b)
The blue wire is B (or a) - doesn't matter

And two more wires are tied together and soldered to the shield, so they are ground!
And since I have the spec sheet for the Ditron wiring, I know where to solder the wires to the DB9 connectors. And since I will be ordering two more glass scales from Ditron for my Lathe, I will use this same information to remove the Din7's from my old DRO head and put DB9's on the reader head instead!

[mcostello]

Glad You figured it out, You lost Me at DB9.

[John Evans]

Me toooooo! Black art !! Burn him at the stake!

[WJH]

Dang nabbit! My DB9 connectors appear lost in the mail, and Radio Shack is out of business! Nothing irritates me more when I have to leave back on a 5 day work trip and things are in limbo!

[WJH]

Well damn, my new Z axis glass scale did not work! I was incredibly bummed out... Then I took out my logic analyzer which I used to map out the signals from the older scales... Turns out that the B output was not working!
I took apart the reader head, and removed it from the glass scale. Really quite simple, and looked at the construction. Really demystified the whole system for me... Anyhow, upon looking at the B wire connection to the reader head, I noticed it had a poor solder connection... It now works, with some fresh solder on the connection, my scale is good to go!
Still waiting for my DB9 connectors. Have since ordered them from Digi-key which is what I should of done from the start