JMC motor stepper servo's

[john-w]

Hi all,

I am converting a mill to run with JMC IHSS-86-80-70 servo's. These are 7Nm 80 Vdc supplied stepper servo's. According to the JMC manual the step and direction inputs can be controlled by 5-24 Vdc signals .

If I connect the Masso directly to the motors they run erratic and only one way. On the oscilloscope I noticed the signal from Masso swing between 0 to 4,5 V with quite some noise referenced to 12V neg.

Does anyone have experience with JMC and Masso?

Thanks and regards, John

 

[masso-support]

Hi John

How have you connected the drive to Masso?

Are you using common ground or differential connection? Can you provide a drawing?

Please ensure that you have configured the maximum and minimum travel for the axis. Ensure that the maximum travel value is larger than the minimum value or you will get one direction travel.

Cheers Peter

 

[john-w]

Hi Peter , thanks for the quick reply. The differential outputs are used the same way You would connect a leadshine controller as the input circuitry looks much the same. The schematic is uploaded .

Maximum and minimum travel are set to + and - 3000mm. The motors have been tested with a 12 v squarewave and ran fine . The motors have also run on Arduino outputs, which gave no problems ( these are not differential mind You ) .

Next step may be connecting with -12V as reference unless You suggest otherwise

Kind Regards , John

 

[masso-support]

Hi John,

Just a couple of things to check.

Make sure all of your axis have been configured as unused axis with 0's in them can cause problems. Just put some dummy values in the axis if you are not using them.

Test the jogging using the mouse on the jog screen buttons as we have had keyboards and pendants in the past that didn't work properly and so caused issues and making it look like the axis wasn't working. Also check that the DRO on the axis you are jogging is changing in both directions showing movement as expected.

If these don't help you could try connecting in common ground mode as the output voltage is a little higher than differential mode and this could be the issue.

S+ to PUL+

S- not connected

D+ to DIR+

D- not connected

GND to PUL-

GND to DIR-

If it still doesn't work can you take some voltage readings across the direction of the drive. You may need to reverse direction to get a voltage reading. It will help determine the loading.


Regards Peter

 

[masso-support]

@john-w can you share a link to the drive user manual?

 

[john-w]

Hi Peter,

as You suggested I have tried a few things . The DRO's are counting up and down , and the pendant is working as well. ( my mentioning -12V should have been GND or 0V, sorry!)

i enclosed some pictures of the scope on the outputs .

I connected according to Your previous post, which had no results.

I also connected the Masso differentially to an ST4045 stepper driver , which ran fine .

Then I cobbled together a differential signal amplifier, with S=S- as inputs and Signal- GND as outputs and connected those to the JMC STEP+and STEP- inputs , ( 10 V pp ) and the motors ran fine .



Concluding all this leave me with a few options and questions :

Is the noise on the Masso outputs normal?

4.5 Vpp is not enough to drive the JMC inputs. The manual states a minimum of 5 V and a maximum of 24 V, I d like to be well above the 5 v bottom limit to get a well defined threshold.

I'll build a signal convertor for all axis, which is not really a big deal.

I'l keep You posted and next post will include a schematic of the circuit I used when everything is completed and tested.



Thanks for now an cheers .



John

 

[john-w]

A few more scope pictures ........

 

[masso-support]

Hi John,

Thanks for the update. It does indeed look like the drive does not like less than 5 volts and your solution is looks great.

I honestly can't tell you about the noise as I do not have a scope with which to test this myself. I really should get one as they are handy to have. I was wonder if your scope lead is grounded and if that is why you are seeing noise. If I read the scale right it looks like a 9 or 10khz signal. Could it be coming from a switch mode power supply? Just a guess.

Glad you got it moving.

Cheers

Peter