PMDX 407 AOut voltage

[JW]

I am running a 407 with a Hitachi NE-S1 VFD. (The mach4 build is 2238 with the 0.17.86 plugin)
The fwd/rev signal is through the 422 relay. The speed control and directional control to the VFD are both working. However, the motor will continue to spin at a very low RPM (.4V Aout voltage) when I try to stop the spindle in mach4 (M5 is commanded)(I'm not using a signal from the 422 to the VFD for stop) . At this point, the PWM led appears to be out but the RUN led is still bright. Aref appears to be 11.5V and the VFD is set up for a 0-10V input signal. As of now, the RUN led remains on whenever the 422/407 is powered (with or without ref voltage, mach launched or closed)? I found a start/end freq setting adjustment function (for external analog input) for O/OI on the VFD side. Is there anything I should be looking for on the mach/PMDX side?

Thanks,
-Jim

[Bob at PMDX]

The "Run" LED remaining lit at all times, even with Mach4 shut down is very suspicious.  When you say "the speed control and directional control to the VFD are both working", do you mean that the PMDX-422/407 combo is able to control the direction and spindle speed in response to "S", "M3" and "M4" commands in Mach4?  And the PMDX-407's "Run" LED remains lit even when the PMDX-422's "Outputs Enabled" LED is off (which it would be when Mach shuts down)?

Let me verify some really basic things:
- The PMDX-407 in plugged in to the 422 so that the 407's circuit board almost touches the 422's relay?
- The mounting holes in the 407 line up directly over the 422's mounting holes?
- Jumper JP1 on the PMDX-422 is set to "On"?
- Do you have anything connected to J2 on the PMDX-407 (the 2-position screw terminal)?

I'll have to ponder this a bit more as, aside from a component failure or a short circuit, I cannot explain this behavior.

As for the spindle running at a very low RPM after an M5 command - the PMDX-407's analog output cannot go all the way down to 0.0V.  The lowest voltage is somewhere around 0.4V.  That means that you should have J2 on the PMDX-407 connected to a "run" signal on your VFD (the above issue with the "Run" LED not withstanding), or configure your VFD to ignore voltages below approx 0.5V (or 0.05 times full speed for a 0-10V input range).  It sounds like you found that setting.

Bob

[JW]

Bob,

The combo is able to control the speed with varying "S" commands and will reverse with "M4" command. The RUN led indeed will remain on with mach4 shut down.

- The 407 is correctly aligned on the 422.
- The JP1 on the 422 is set to on.
- 24V (COM) from the VFD is routed to the J2 COM. The RUN on the 407 is routed to the COM on the 422 relay. The FWD signal to the VFD is from the NC on the 422. The RV signal to the VFD is from the NO signal on the 422 relay. The VFD signal inputs are in sink logic with the absence of FWD/REV signal as a stop signal. The relay on the 422 is set to pin 1 for the rev command. Currently, I don't have an output signal set for the FWD command in mach4.

Everything was working fine when I ran it a week ago. The other day I plugged in the USB from the 422 and a spindle speed error (I don't remember the exact verbiage...should have written it down but have since reloaded mach and the plugin) continued to manifest. The computer seemed like it was continuously finding the 422 (beeping as if finding the device over and over again).  I have reloaded mach and the plugin and the 422 seems to be working as advertised.

I will let you know how the VFD start end freq setting adjustments turns out.
Thanks,
-Jim

[Bob at PMDX]

Now that I see how you have the PMDX-407/422 connected to the VFD's Fwd/Rev inputs, it should indeed halt the spindle when the PWM shuts off (either from an "S0" command or "M5").  Setting the VFD's "start freq" is really just a stop-gap to cover up what appears to be improper operation of the PMDX-407.

Since the PMDX-407's "Run" LED remains lit at all times, it appears that something is wrong with either the PMDX-407 or the PMDX-422.  I haven't yet been able to find a way that incorrect wiring to the PMDX-407 can affect the RUN LED.  I'll talk this over with Steve (my boss), but I think you will need to send your boards back to PMDX (don't do that yet, we will let you know if/when it is time for that).

Everything was working fine when I ran it a week ago. The other day I plugged in the USB from the 422 and a spindle speed error (I don't remember the exact verbiage...should have written it down but have since reloaded mach and the plugin) continued to manifest. The computer seemed like it was continuously finding the 422 (beeping as if finding the

Sigh...  Error messages are important.

24V (COM) from the VFD is routed to the J2 COM.

Since you say the VFD inputs are "sink" logic, I presume that the "24V (COM)" is the same as the "L" terminal that I see mentioned in the NE-S1 Quick Reference Manual.

Bob

[JW]

Bob,

Update...My beloved wife informed me that my laptop took a tumble last week (while not hooked up to the 422). Apparently it hit on the corner by the USB port I have been using to plug into the 422. The USB connection is very sketchy now and I think the 422 was having communication issues when it was plugged into that port. I inadvertently switched usb ports while troubleshooting leading to more confusion as to why the 422 was working under certain circumstances. I believe the 407 RUN LED issue resulted from a shorted usb connection at some point.

Everything else on the 422/407 seems to be working fine when plugged into another USB port on the laptop (still have the 407 RUN on). I have hooked up output 14 of the 422 to an off board relay for the FWD spindle command. The REV is still using the relay on the 422. Everything is working as advertised...no need to adjust the start freq at the VFD. 

I haven't found any other issues yet. Crossing my fingers.
Thanks,
Jim