Mesa 5i25/7i76 + driver leadshine DM2282 digital

The hardware stepgens, are controlled a like a servo. Linuxcnc sends a velocity command to the stepgen, and the hardware step generator sends a position feed back to Linuxcnc, these are plugged into the PID loop. This works better than just sending the postion commands to the step generator, and helps smooth out problems introduced by jitter in the control PC's real-time system.
P is the P term in the PID loop. P is for proportional. (google PID loop for more detailed info)

Thanks to all, today we will test it and them we comment the news.

Thanks.

Hello Folks, that is what we have made:

changed P parameter to 1000 (nothing happened )
changed setp pid.N.maxerror .0005 to 0 (Nothing happened )

after doing some change we edited the scale parameter in the INI and it starts to work correctly.
Next weekend we are going to make more deep testing and then I will tell you how it went.

Thanks

changed P parameter to 1000 (nothing happened )
changed setp pid.N.maxerror .0005 to 0 (Nothing happened )

You may not have noticed the change in behaviour
but these parameter changes are required

Hi guys!
The engine makes noise being stopped, as I put the principle can not give the correct values to the parameters.
Step_Len: 2500
Step Space: 2500
Dir_hold: 5000
Dir_Setup: 5000

only accepts exceeding 5000

today we have entered these:
Step_Len: 5000
Step Space: 5000
Dir_hold: 6000
Dir_Setup: 6000

PCW wrote:

First thing I would is change the P term to 1000 (was 50)

The wiring looks correct but sometimes the differential outputs do not work very well with high input
current drives so it might be worth trying with common ground wiring (connect PUL- AND DIR- to ground instead of 7I76 outputs and leave the 7I76 dir- and step- outputs unconnected)

You might also verify that the 5V at the 7I76 is not less then 4.75V or so

We not yet verified the voltage, tomorrow we will.
We also want to change the connection of the cables, so what would you say PCW:



Doing this will improve?

Have you had any luck solving this issue? I am experiencing similar problem now using the 5i25/7i76 and leadshine DM556 drives.

What exact issue do you have?

I have to set Step Len and Step Space = 3500 to get the motor to move, but the drive manual specifies 2500. I'm not sure if this is related, but I also get a joint following error with speeds above ~400RPM. I am able to get much faster speeds out of the motor when using the autotune program that came with the drives. I have also set the P = 1000 and pid.N.maxerror = 0

Hello Squan09 unfortunatly we couldn't solve the problem completly. what we do was make a downgrade from linuxcnc 2.7 to 2.6 that solve the problem a bit but we are not able to set the step space less than 3500. at 2500 the motors doesn't move. tomorrow i will post my configuration maybe it can be useful for you.

Thanks. Do you know roughly how fast you are able to move the motors in RPM? Is it the servo period that will limit the max speeds or are there other parameters that I can change to maximize RPMs?