Mitsubishi MR-J3-XX"A" drive + 7i94 config?

I have completely given up on trying to get a functional STMBL drive built. I've had PCB's made from two different sources, scrounged STM32F303's from 4 sources, tried compiling on four different computers on two different operating systems, and have never gotten the high-voltage control board to work. I bought a 7I94 8-port SSerial card to drive them with, and given the difficulty in obtaining anything these days I'm hoping to get it to work with Mitsubishi Servo drives.

After the STMBL failure, I was planning to get one of Dmitry's SSC-Net cards to control the Mitsubishi servo drives over the optical interface, however after the drives turned up in the post, they're not the "B" series optical interface, but instead the "A" series copper interface. This gave me hope that since they can use analog input, digital pulse train input, or RS-422 input for control, maybe I can use the 7I94 to do RS-422 control.

Does LinuxCNC support serial control of the Mitsubishi servo drives? If not, is anyone interested in working with me to add support for them? If not, I have a 7I96 that I could use for step/direction, but it will involve a LOT more wiring.

The manual for the drives is linked here, and in Section 13 it shows that RS-422 control is supported in direct wired and bus-wired systems. I'm still trying to learn the details of the control interface, but I think that RS-422 control could work!

dl.mitsubishielectric.com/dl/fa/document...030038/sh030038l.pdf
 

the rs-422 interface on mr-j drives can be used to read/write drive parameters, for monitoring, alarms etc. it is not intended for motor control. though the protocol has a "test mode" commands which can spin the motor - it is not suitable for real-time control

so. as i said, your options with those drives are either position control with a pulse train or speed control with analog +-10V

andypugh wrote:

That's unfortunate. I have occasionally had to try a few times with the boot pads to get the board to show up on USB, but after that it has been OK.
I could try programming your HV boards for you, if postage to the UK is do-able?
 

Andy, I will build up a set of 3 HV boards again and see about getting them to the UK. It shouldn't be that difficult. Do you want me to send the LV boards? They have all flashed and communicate with Servoterm, but none of them have ever communicated with the HV board, best I can tell.

Dmitry, I am OK with using a pulse train to control these, I just was reading through the manual and saw where there are commands in the RS-422 command set to drive the servos with in position control mode. Do you have experience with the Mitsubishi software for these drives or did you build your own config tool? (You've done so much hacking on these things, I'd think you're probably the foremost expert on these drives.)

I can still use the 7I94 here though, and configure an RS-422 port to do drive communication and configure the 25 pin expansion port to do the pulse trains needed, the MESA 5A_BOB firmware sets up 8 serial ports plus 5 hardware stepgens, a PWM output, an encoder input, and some GPIO. Might not be as good as using the 7I96 that I also have in the box. Both options are still available.

it is possible to use rs-422 (or USB, which is mostly equivalent) to issue positioning commands in test mode for auxilliary tasks like a toolchanger carousel, chip conveyor or the like. but it is severely limited. it can't serve as a normal linuxcnc joint. so i would not consider this way of communication at all, except for initial setup... stick with pulse train/analog.

for MR-J3 drive configuration mitsubishi has MR Configurator (SETUP221E) or MR Configurator 2 software. the former is free, i believe. it has some useful features for tuning like the "machine analyzer" which can do bode plots and helps with filters setup...

I have not be able to find a download for MR configurator, just MR configurator 2. Maybe this week I'll get a test board up and working, these drives were advertised as pulled from working machines, but I won't really know what I have until I power them up. They probably need the electrolytic capacitors changed in them, given the dates and how hard these things get run.

I have HC-KFS73 servos to drive, I have not found any list that says these can't run those servos but then again I can't find any list that says they can, either. The J3's run other HC-xFS servos and I found a list that says they can run the HC-KFS43, so I hope I haven't screwed that up too.

I also have two HG-KR32B servos that I was going to use for a tool changer or a rotary axis. Don't have the smaller drives yet but they're very inexpensive in the -A format, and downright cheap in the -B format.
 

yes, MR-J3 amps will run HC-KFS motors. you'll need to set the parameter
PC04=0100
if drive/motor sizes don't match (alarm 1A), set PA19=ABCD, power-cycle the amp, set PH18=1, power-cycle again.
HG-KR should also work. although they are from the next MR-J4 generation, their encoders emulate older OBA18 and provide motor constants to the drive