MELSERVO Help, Replacing Sony MILLSTATION

Let me begin by saying that I am a toolmaker, not an engineer. I have done a decent amount of research on my system, but there are a couple answers that elude me. I am using MELSEVO J2 amps and I am unclear as to what the minimum necessary connections are to operate these servos. I am sure I will run into other questions as I progress, but this would clear a decent sized portion of the path for me. So if anyone is familiar with the MELSERVO setup (my diagram uses speed mode) I would really appreciate a bit of guidance. Thank you.

You are correct, they are outputs to the controller. As far as the control that is where I am a bit stumped as well. My intention is to run with step/dir, which was Mesa's recommendation when I showed them my hardware. I hate to ask anyone to weed through the whole manual, so I included the wiring diagram for the amp with hopes that would be all you might need, if not here is the link to the manual if you are interested in having a look.

MRJ2A

Thank you for having a look, hopefully Im not too far over my head.

I think if you want to control the drives with step/dir signals, you may be looking at the wrong page in the manual. Can you look to see and show us the diagrams for Position Control (rather than Speed Control)?

I think the pages you want to look at are pg.2-4 and pgs.3-20,21 for how to connect your step/dir signals. Those would be pins 3&13 for the step and 2&12 for the direction on connector CN1A. Those would connect to pins 11&12 and 13&14 on TB2 on your 7i85S card for the first axis. Don't forget the 5v, ground, and enable signals for the axis as well. You also need to be sure the parameters for the drive are set properly for the type of input you use.

So is there a better way to control this amp with the 7I85 without using step/dir? I was under the impression that velocity mode was ideal, and when I contacted MESA with my info they suggested using the step/dir input. If this is as good a way as any for a knee mill, or just a simpler method for a noob to get this chunk of iron running until I am knowledgeable enough to upgrade properly, thats fine too.

Either way, I will begin researching the method you supplied and see where I get, thank you for your help, looking forward to showing this puppy off when I get her finished. Have an awesome day.

Step/Dir, CW/CCW (up/down), or Quadrature (like an encoder) are pretty much your only options with the 7i85S. All of which should work equally well, and would even use the same wiring schemes. If you have the 7i85 (the lack of an S is important) you might be out of luck entirely (it has smart serial connections instead of step/dir). The only other way would be to use an analog command, with a 7i77 card. That might actually be a better option, but is a more expecive card (and you don't have one).

As to what would be the simplest way, probably depends on how the old control was connected. If the old system used step/dir, that that will be simpler. If the old was an analog velocity command, that will be the easy way. If you change the command input, you are going to have to reconfigure and retune the servodrives using their software... If you don't make those kind of big changes, than tuning should be minimal (or not at all in the case of digital position contorl).

You are correct sir, looks like Im on hold for a few days while I order a 7I77. Sorry for taking your time.

I have a millstation nu -20 I added the third axis but need nu-30 software to complete operation any help with spare parts would help me . THANKS