Many thanks !
I reconnected as suggested, and it works first try.
I am * extremely * impressed, and will be repeating my very favourable impression of your technical support and products.
I hope to move to Mach4 soon, but wanted to get a working version first.
Servos now work as expected, on the test bench.
Machine is a scratch built VMC, in steel,about 2000 kg.
Using 32 mm ballscrews, and a submicron step size.
Again, I am very, very grateful.