Quote Originally Posted by Lahdiel View Post
Ah okay, i've never seen a lot of those acronyms before, i'm not using a VFD as its for a 190vmc conversion the controller is a lenze534 and i've already sorted the reverse relays for that
I just got the spindle working controlled from an external power supply too so i think im sorted with those connections

I'll try these suggestions and see if i can get anywhere with it
Okay, if I was trying to sort this out this is what I'd be doing:-

1) On the Lenze, establish the +V, Gnd and sense lines. On the Lenze 531, these are pins 9, 7, 8 respectively. The user manual should confirm that, and it sounds as though you know these already with the speed control that you have. From herein I'll use those acronyms ("+V", "Gnd" and "Sense") in relation to the Lenze controller. At least one Lenze manual refers to these as "E", "A", and "S".
2) Confirm Lenze.+V is 10 Volts, or thereabouts wrt the Lenze.Gnd terminal. Don't proceed it this is wildly off. Note, Lenze.Gnd may be (will be) floating above equipment earth - so take care with measurement and avoid shock hazard.
3) On the USB-BoB, confirm with DMM on resistance range, Open-line (OL) - very high resistance (>10MR) between terminal [BOB.ACM] and [BOB.GND]. Do not proceed if not.
4) Repeat for [BOB.10V], to [BOB.GND]. Expected: Open-line (OL) - Do not proceed if not.
5) Repeat for [BOB.AVI] to [BOB.GND]. Do not proceed if not.

At this stage you can expect the BOB variable output to be electrically isolated from the main BoB circuitry, Power everything off.

6) Connect [BOB.ACM] to [Lenze.Gnd]
7) Connect [BOB.10V] to [Lenze.+V]
8) Connect [BOB.AVI] to [Lenze.Sense]

Test. I would not connect the PC to the USB board until I've observed the absence of magic smoke from the BoB.

But that's just me.