7i76ED - analog input from VFD

For a number of reasons I've abandoned my attempt(s) to use a servo drive & motor as a spindle. Nothing to do with Lcnc or Mesa... just tired of trying to get just the 'right' combo to do what I want.

Moving forward I've acquired a proper induction spindle motor and suitable VFD. I'd like to send the VFD analog output signal (actual current) to the 7i76ED for eventual use by Lcnc as a load meter and/or adaptive feedrates.

Analog out circuit from the GS3-23P0 VFD below, but I'm not sure how to connect it to the 7i76's analog inputs. Those inputs appear use the field power as the reference voltage and are intended for use with a pot... but the VFD appears to supply the 0-10v and not just act as a variable resistor.

Any suggestions?




EDIT:

Just had another look at everything... does VFD-AO connect to 7i76 I00(through I03) and VFD-ACM connect to Field Power pin VIN- ?

Yes. ACM to field power common (negative) AO to 7I76E/7I76ED input 0,1,2,or 3

Thanks much!

PCW,

Finally getting back to this project and now that I'm in front of the cabinet I could use some clarification.

I'm using the 0-10v function from the 7i76 to control spindle speed.  That means the following connections:

7i76-TB4/1 (spindle -) > VFD/ACM
7i76-TB4/2 (spindle out) > VFD/AI1
7i76-TB4/3 (spindle +) > VFD/+10V

But... your last message indicated for VFD analog output to 7i76 analog input I should connect:

7i76-TB6/1 (I00) > VFD/AO
7i76-TB1/V- (field power V-) > VFD/ACM

Before let the magic smoke out, I just want to double-check that I'm supposed to connect ACM to both TB4/1 (spindle -) and field power V-

If not, can you suggest what the connections are to use both analog in and out from the 7i76 to the VFD?

Thanks much,

Ralph


 
 

I'm looking at this again (and again), and I realize I should just see if PCW (or anyone) can double-check the whole connection scheme for me.

First... the 7i76ED is sinking output, so I should set the GS3 VFD to sourcing input mode (yes/no?)

Spindle Control (digital)
7i76 TB4/08&06 (Ena+ & Dir+) > VFD/+24V
7i76 TB4/07 (Ena-) > VFD/DI1
7i76 TB4/05 (Dir-) > VFD/DI2

Spindle Control (anolog)
7i76-TB4/1 (spindle -) > VFD/ACM
7i76-TB4/2 (spindle out) > VFD/AI1
7i76-TB4/3 (spindle +) > VFD/+10V

VFD Fault/zero speed/ect (digital)
7i76-TB1/V- (field power V-) > VFD/DCM
7i76-TB5/17 (O08) > VFD/DO1
7i76-TB5/18 (O09) > VFD/DO1
7i76-TB5/19 (O10) > VFD/DO1

VFD Load (analog)
7i76-TB6/1 (I00) > VFD/AO
7i76-TB1/V- (field power V-) > VFD/ACM

Still not sure about the VFD's digital outputs.  Looks like it's a sinking output on the diagram below..maybe meaning it's not compatible with the 7i76ED's sinking inputs?

-R

 

Yes, ACM needs to be connected to field power common (-)
since this is the common for the 7I76ED analog inputs.

If you are only connecting the ENA and DIR from the 7I76ED
spindle interface, You can use sinking inputs, but if you plan to
use additional inputs on the drive connected to field outputs,
you would need sourcing inputs.

ENA/DIR act like relays or switches, so either sinking/sourcing scheme would work if I don't use other digital inputs on the drive, got it.

ACM to both field power and spindle -, got it.

What about the digital outputs from the drive?  Are they compatible with the 7i76ED?  Not sure how to connect those, and I think my earlier config had a typo as I didn't have a connection to DOC (had DCM in error)

VFD Fault/zero speed/ect (digital)
7i76-TB?/??? > VFD/DOC
7i76-TB5/17 (O08) > VFD/DO1
 

The sinking digital outputs are not directly compatible with
7I76XX inputs, but could be read using an external pullup
resistor to +24V. (say 2K 1/2W)

Thanks. I'll skip the digital outputs and just use the R1 relay for a fault signal. I'll let LCNC figure out the zero-speed stuff for ATC safety via the spindle encoder.

Appreciate the help!

-R