pmdx 424 and pmdx 407 speed control

[Mike Abbott]

Apparently I'm either tired or missing something (probably both) but i've got the following setup:

pmdx424 (works great)
pmdx 407 (just installed)
huanyang VFD
Standard 1.5HP 3PH motor

The VFD/motor will function find using the control panel on the VFD for changing speed and for/rev so the wiring at least is a known good.

I've just installed the 407 and started the config of the VFD and gotten the run portion of the 407 working now and it starts up at the min speed setup in parameter 072 in the VFD.

The speed setup has me stumped.  I've wired A-GND to ACM, A-Out to VI.

A-Ref has me stumped, when I connect it to the +10v terminal on the VFD, the spindle starts up at a VERY high speed.  When it's just disconnected, the system starts at the min speed setup in parameter 072 as well as when I connect it to VO on the VFD.

As far as how I have things in mach4 and the plugin setup it's as follows:

Plugin spindle has the 407 selected as the output and nothing else checked.

Mach4 has the setup 0 selected with some reasonable smallish numbers (min of 500 and max of 3000 RPM setup).

I've got a standalone index setup with a hall effect sensor which works and displays accurately.

I'm a bit stumped on how to troubleshot the setup so any help would be appreciated.  I'm attaching some pics of the wiring and terminals for reference (pics were taken with the white wire attached although I wound up disconnecting it).

Mike

[Bob at PMDX]

The connections from the 407 to the VFD look correct, including the 407's Aref to the VFD's "+10V".

Did you change the VFD parameter (PD002?) to select operating speed from external terminals?  It appears so since you are getting a reaction to the PMDX-407, but I gotta ask just to be sure.

Do you have PD070 set to 0 (for 0-10V analog input range)?

Are you entering an "S" command or somehow selecting the spindle speed in Mach4?

When you turn on the spindle in Mach4 and change commanded spindle speeds, does the "PWM" LED on the PMDx-407 change intensity/brightness?  For example, an "S3000" (i.e. full speed) command should make the LED pretty bright, and an "S500" command should make the LED noticeably dimmer.  Do you see these changes on the PWM LED?

Do you have a volt meter or DMM (digital multimeter)?  If so, try commanding the spindle to full speed ("S3000") and then measure the voltage between the "Agnd" and "Aout" terminals on the PMDX-407.  It should read very close to 10V.  Then set the spindle speed to "s1000" (1000 RPM) and again measure the voltage.  You should now read something close to 3.3V.

*** WARNING  *** Be VERY VERY careful when measuring the voltages on the PMDX-407's analog output terminals.  These are isolated from the rest of the PMDX-407 and PMDX-424 and *could* be at the AC mains voltage.

Bob

[Mike Abbott]

OK, have it commanding speed now with the a-ref connected to the +10v terminal.  The VO terminal does something else and I have no idea what it is.  Think where I got concerned/confused is I had the parameter 72 set to 400hz (which is just a tad outside how fast this motor can or should go).  Now the question I have is how to tune the rpm settings properly.  I'm guessing that parameters 72 and 73 have to be set to the realistic values of where I want the motor to run at and then mach4 setup with estimated values where I think the rpm should be and then use the POT on the 407 to fine tune so that measured RPM and commanded RPM match fairly close.  Am I near being correct there?  Last question is, what is the default RPM that mach4 will startup at if you just turn on the spindle?  Is it the last commanded speed and how is that determined upon a fresh boot of the system?

Mike

[Bob at PMDX]

OK, have it commanding speed now with the a-ref connected to the +10v terminal.  The VO terminal does something else and I have no idea what it is.

The VO terminal is a 0-10V *output* signal that is proportional to the current RPM (basically an output signal to mirrors the input control voltage from the PMDX-407).

Think where I got concerned/confused is I had the parameter 72 set to 400hz (which is just a tad outside how fast this motor can or should go).  Now the question I have is how to tune the rpm settings properly.  I'm guessing that parameters 72 and 73 have to be set to the realistic values of where I want the motor to run at and then mach4 setup with estimated values where I think the rpm should be and then use the POT on the 407 to fine tune so that measured RPM and commanded RPM match fairly close.  Am I near being correct there? 

I don't know about the PD072/PD073 settings, that is beyond my limited knowledge of VFDs.  To "calibrate" the PMDX-407, command Mach4 to run the spindle at the max RPM ("S3000" if 3000 RPM is your max).  The adjust the pot on the PMDX-407 until the VFD gets as close to that RPM as possible.

Last question is, what is the default RPM that mach4 will startup at if you just turn on the spindle?  Is it the last commanded speed and how is that determined upon a fresh boot of the system?

When you first start Mach4 the spindle speed is zero.  If you enter an "M3" command without a "S" command, the spindle will be commanded to zero RPM.  Once you enter an "S" command, that becomes the spindle speed when ever the spindle is enable, until you enter a new "S" command.

Bob