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Author Topic: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"  (Read 22368 times)

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #30 on: October 30, 2014, 10:46:32 AM »
Thanks for the reply simpson36. I understand the core connections you mentioned and have worked with steppers that used CCW/CW or step/dir also. Servos are new to me but the Mitsu inputs are hard to to understand in the 400+ page manual. Add to that limited docs on the CSMIO and its a head banger.

Reply back from CSMIO:

Signals you have pointed are unneeded as the +/-10V signal decides about motor revs direction and motor rotation speed.

      For correct servo  drive operation in speed mode you need signals:
      1) +/-10V
      2) servo on
     3) reset
     4) ready (ready signal after logic state reverse gives servo alarm signal)
     5) encoder sygnaƂ


On the speed control diagram he highlighted P15R/VC/LG for the +/-10V signaling. Don't want to magic smoke from the $800 controller and appreciate everyones input.
Heading to work now so will check manual when I get back.

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #31 on: October 30, 2014, 02:22:33 PM »
Simpson36 is correct with regards to VC being the connection you should make rather than P15R however I think you will need to also connect LG as you will need a reference for the voltage.

Hood

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #32 on: October 30, 2014, 02:27:32 PM »
Here is what the manual states.
Hood

Offline simpson36

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #33 on: October 30, 2014, 03:32:32 PM »
Here is what the manual states.
Hood

Hi Hood,

Long time no speaky.  Somehow I am still being notified on this thread.  

I see you are still most generous with your time. I only commented when I saw your name here. I still owe you big for all the help you have provided me in the past, so I can't loose the rare opportunity to respond in kind.

Anyway, P15R and its ground (LG) I believe are isolated from the rest of the control side and the analog voltage would come either from 15R (thru a pot) or an external source but in either case your would want the isolated ground to avoid the pitfalls I mentioned earlier. Good catch on your part.

Mitsu drives have very sensitive electronics and can recognize and use a pretty weak signal, but the consequence is that they are also overly sensitive to noise and especially ground loops. They will pick up the tiniest noise and treat it as a signal. I have never had to go as far as putting pull-up or pull-down resistors on them, but they do need and expect a properly quieted system.

We are all supposed to do all the good things needed to avoid ground loops and shield the control signals . . . .  but a lot of drives let you get away with being sloppy about that part of the job. Mitsu is not one of them.

Last comment: You can reset the drive after a fault by pressing the rightmost button on the drive. 'Ready' is not needed by MACH because MACH only looks at E-stop (ALM in Mitsu speak). The drive kills the alarm on reset, so you do not need to mess with 'Ready' (RDY, or something like that, I think) unless the controller needs it for some specific reason.

A complication of the Mitsu E-stop (ALM) is that it goes off when you disable the drive, therefor, if you want to use the enable/disable function without E-Stopping MACH each time, you must set up a surrogate e-stop signal to 'hold' MACH running while you have the drive enabled. This is actually not very complicated, but I won't go into that unless someone needs it.  This may be configurable in the new J4 (I don't know), but to my knowledge the behavior is non changeable in the J2S that we're talking about here.

The 'Ready' signal behaves differently, and there is also a complication in using that as the E-stop, but I can't remember what it was at this moment. Been a long time since I ate that elephant.

Q: why do you need an encoder signal?


Offline Hood

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #34 on: October 30, 2014, 03:54:02 PM »
Encoder signal is needed because it is a closed loop control, Machs DROs also get updated from the encoders position even when in E-Stop or manually turning the motors.

Hood
Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #35 on: October 30, 2014, 07:02:04 PM »
Hey All,
I was feeling overwhelmed by the whole servo setup but with the feedback I am more confidence now - thanks.
Attached is the recommendation sent by CSMIO and it matchs Hoods layout.

More questions ... you kinda knew they were coming   :)
IP-A was improved over IP-S due to its analog signaling and DRO feedback.
In the manual, P15R='15VDC power supply ' and LG='Common terminal for TLA, TC, VC, VLA, FPA, FPB, OP,MO1, MO2 and P15R'
These don't seem like differential inputs (?)
There is no separate directional signal required with P15R/LG so are these ccw(-) and cw(+) on these inputs?

Also, Pg 3-26 of the manual shows differential going to PP/PG (CW) and NP/NG (CCW).
These would be digital inputs which the IP-A should be able to handle in case analog inputs are issue?

(I will gladly post details of the final configuration after setup so it helps others)

Offline Hood

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #36 on: October 30, 2014, 09:01:03 PM »
Ok first thing to note is my drawing previously was wrong with regards the analogue signal, it should have been between VC and LG and NOT P15R as I said.

Now CW/CCW, you do not need them, the analogue signal tells the drive which direction it is to go. -10v to 0v is one direction 0v to +10v is the other..

The second analogue input shown on the above pic is not required for your purpose as it is to limit torque if required, you do not need to do that.


So to summarise, I think this is what you need.
You need the E-Stop input, that would be part of your machines E-Stop chain, probably via relay/ opto to connect to SG to avoid Gnd loops that Simpson mentioned.
You need the SON, that is the Enable for the drive, again relay/opto to connect it to SG.
You need to short the ST1 to  SG as that will allow your rotation as per previous snippet from the manual I attached. You could decide to use ST2 instead but you can not use both as that would lock the drive, ie no rotation.
You need to connect VC to the analogue output from IP-A for that axis.
You need to connect LG  to the analogue Gnd output for that axis on the IP-A.

The other connections you require are the encoder outputs from the drive, they are differential and connect to the encoder inputs on the IP-A.
The Ready may be required if you wish to input a fault signal to the IP-A, that is definitely recommended as it will let the IP-A know if an axis faults and thus motion will be stopped on all axes. This would happen anyway as you would get a following error from the IP-A as the axis is not where it is meant to be, but it is better to have the additional fault signal as an extra safety feature.
Lastly it is also good to have the reset connected to the IP-A so that the IP-A or Mac can reset a drive if it has faulted, as mentioned by Simpson36 you could just press te button on te drive but easier to let the IP-A handle it automatically or ave a screen button in Mach.

As the SON and Reset need to be shorted to SG to work then you would need to use a relay or opto to connect them, having the relay/opto controlled via the IP-A outputs.

Oh also you need to short  LSP and LSN to SG.

I think that is it.

Simpson36 has mentioned about the ease of setting up a ground loop on these drives so I would listen to what he says on that matter.

Hood
Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #37 on: October 30, 2014, 10:03:07 PM »
That explains it really clearly - appreciated!
Will draw out everything on the weekend one more time and order the IP-A.
Thanks

Offline simpson36

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #38 on: October 31, 2014, 02:08:17 AM »
Encoder signal is needed because it is a closed loop control, Machs DROs also get updated from the encoders position even when in E-Stop or manually turning the motors.

Hood

I don't think the drive will operate at all without the encoder signals from the motor to the drive. THe drive reads a lot of data from the encoder, not just position.

The drive is able to 'echo' encoder data, either in original or altered form, to an external device, so it should be possible to supply encoder data to the controller if needed, but I doubt this would equal a 'closed loop' back to the controller because the drive is most likely going to react to its own data received from the actual encoder.

To accomplish a loop between the motor and the controller, I think you would need an 'amplifier' and not a 'drive'.

In considering how to set up a 'reset' it may be preferable to have the operator do the reset manually so that he/she can observe the alarm code before resetting the drive. Note however that the alarm code history is available from the drive, so if the controller is allowed to reset the drive, then if unexpected or unexplainable faults continuously occur, the operator can acquire the alarm history from the drive to figure out what is causing the repeated faults. If, for example, the faults are from an overheated motor, then automatically resetting the drive immediately will likely result in an another fault.


 

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Re: Please help W/ Mitsubishi MR-J2S and MACH 3 "PLEASE"
« Reply #39 on: October 31, 2014, 03:54:28 AM »
Simpson36
When using Analogue command the drive is basically being used as an amplifier,  the CSMIO/IP-A  looks at the encoder feedback and decides how much voltage to send to the drives analogue command input to maintain the correct position/speed/time.

Regards the Reset, yes that is true if it is a continual occurrence, always good to know the reason for the fault condition.


Hood