7i76 SPINENA with Huanyang VFD

I've got the 10v output working right for the huanyang vfd but i'm confused on the SPINENA+ and SPINENA-.
I was hoping this would act like a relay then i could just run DST to SPINEAN+ and FOR to SPINENA- and all should be good,
but it seems that is not the case as it seems to give a high resistance reading when you enable the machine. So it does do something
just not sure what exactly that is lol. Any ideas?

Thanks!
Jake

Nevermind that, even though it appeared that it wouldn't close the circuit, when i hooked up up between FOR and DCM it worked fine. Now when i hook up V1 to SPINOUT the voltage drops to around 5v when it was previously ~10v so i'm only getting ~12000 rpm from the spindle. I've tried different power supplies all 12v nothing seems to help.

If you use a separate 12V supply for SPINDLE- and SPINDLE+ you should get 6V for 1/2 scale and 12V full scale
on SPINDLE OUT relative to SPINDLE-

If the SPINDLE OUT at full scale was 12V and drops to 5V when connected to the VFD analog input
it suggests a wiring error since the SPINDLE OUT signal is a low impedance buffered output.

PCW wrote:

If you use a separate 12V supply for SPINDLE- and SPINDLE+ you should get 6V for 1/2 scale and 12V full scale
on SPINDLE OUT relative to SPINDLE-

If the SPINDLE OUT at full scale was 12V and drops to 5V when connected to the VFD analog input
it suggests a wiring error since the SPINDLE OUT signal is a low impedance buffered output.

This is how i have it wired.

PCW wrote:

it suggests a wiring error since the SPINDLE OUT signal is a low impedance buffered output.

jds8086,
I ordered a 7i76 just today here in old Europe and I have the same VFD.
According to the manual V1 of the VFD can take 0..10V or 0..5V. Check the value of PD070 (value 0=0..10V value 1=0..5V). I suggest you change the supply voltage on SPINDLE+ to 10V. In your case a simple resistor might do the job for you. Also, you might double check PD002, PD072, PD073.

Is the output 12V at full scale? (it should be)
does the 12V supply droop?

The 7I76 analog output consists of a a two pole filter for PWM and a rail-rail opamp buffer.
There is no reason the output should droop unless it is overloaded. Sometimes 10V VFD
potentiometer supplies cannot deliver the approximately 10 mA that the analog out needs
but in this case you can tell by seeing if the power (between SPINDLE- and SPINDLE+ ) droops

I took some measurements.

With the power supply hooked up to the 7i76, and nothing hooked to pin 2, i'm reading 11.79V

Full scale i'm getting 11.18V on pin 2 without the vfd hooked up.

With the vfd hooked up but not powered on it drops to 11.08v on pin 2, but the power supply voltage stays at 11.79v.

With the vfd powered on and running the power supply was still at 11.79v, but pin 2 dropped to 3.9V.

Current draw was .194mA between pin 2 and V1 on VFD.

Looks like there's maybe a problem with the spindle analog out on the last batch of 7I76's
( lot number 14258 only )

This is an issue with the rail-rail op-amp buffers bias setting. The low BIAs setting its using does now work
reliably into loads less than 10K. Anyone that has a problem with the Analog output
these cards may send them back to Mesa for a repair.

The repair can also be done locally and consists of soldering
a jumper between pins 4 and 5 of U17

EDIT
A simpler alternate patch is a .01 uf capacitor from TB4 pin 2 to TB4 pin 1

Jumper from pins 4 & 5 on U17 did the trick. Works great now!

One more for you, how many mA can you run threw SPINENA? I have a PC power supply that runs my cooling pump that pulls 2.6mA to turn it on. The VFD pulls .33mA. Would it be safe to run both of these loads to SPINENA?

Thanks!

Never mind that thought...