Emco PC Turn 55 spindle control

Anyone have any idea what sort of spindle control is this and can it be hooked up to Linuxcnc? Would I be better off buying a VFD? There is no PWM or 0-10v input.  Motor is .35kw 3 phase. 

That looks to my untrained eye like a differential step/direction control.

I think "CLK" means 'clock'
"E" might be enable

Maybe Emco decided that a step/dir spindle control was preferred over analog for some reason.  Wouldn't be the strangest thing they ever did.

My Emco 325-II has a Lenze VFD and is controlled by an analog signal - but that's a rather different lathe than your 55.

However, on my diagram "md current" is identified as the analog-out (i.e. analog reference voltage) from the VFD to the Emco board.

Any pics or specs for the drive itself?

Not at the moment but I'm in the middle of doing up a quick differential circuit. Clk MD is the PDM input(I think) enable is 5v, dir=direction, NI is index,

Forget everything I wrote earlier - it's an analog control.

Found the manual, have a look at page 8 - the Y4A400 000 connections are described better.

The "DIR/CK" connections I mentioned earlier are the encoder feedback TO the drive board.

E is enable (on/off)
N+/N- is the analog speed input TO the drive
IA is the reference voltage
SR is the 'servo-ready' signal - likely an alarm signal.

EDIT - I think, anyway.  Maybe someone else can help, but I suspect if you test IA to ground with the drive powered you should see the reference voltage.

So n+ and n- are the PDM? IA is 10v ? I found a post on another forum attached below. This is for PC mill but should be the same .

I'm confused now too - sorry if I muddied the waters.

I think your best bet is to keep searching for a definative answer from someone who has the same lathe with the same drive.  Looks like there were a few versions used over the years - a Lenze VFD and a proprietary Emco spindle drive (yours, I think).

And some similar models used a DC spindle.

Here's a post discussing a retrofit:

forum.linuxcnc.org/show-your-stuff/41345...-pc-turn-55-retrofit

Maybe that helps?

I'm going to try and find an electrical diagram manual for the mill 50 and cross reference page 8 . They may be wired different

There is no reference to the pin names on the PC 50 mill electrical manual. I don't want to blindly hook up wires if I'm not sure. My controller outputs 0-10v and I don't know if the emco speed input takes up to 10v , it could blow it

Maybe punt and get a small VFD?  You'd be saving a step/dir output if that's any consolation, and can sell the Emco drive to someone who hasn't done a conversion.

I did find the PC Turn 50 electrical manual, but it's identical to your 55 version.