Mesa 5i20 - 7I52S support

We manage to repair (remove resistors) from the board and it behaves much different.

Now I am somehow confused with tunning. VSD/E drive contain its own PID loop (I configured the drive in velocity mode) and it runs super with supplied SW.

With EMC close loop I have problems. How EMC PID works with drive PID? I can run with P=5 or 6, I=0, D=0. I define following error 0.5, if less, I receive error. What is reasonable value.

I believe that I can not correctly tune EMC as motor alone works much better.

Removing the resistors should have made no operational difference (only increasing the output drive voltage slightly say from 4.3v to 5V)

Is the drive still in velocity mode (PWM in sets velocity?)

For velocity mode (and if scaled properly, that is PID feedback, command and output are all in machine units per second (234?)) FF1 needs to be set to 1 and then adjusted a little (say from 0.90 to 1.10) for lowest following error during a fast slew.

Also I believe theres an optional filter in the Granite drive from input command to their velocity loop.
This needs to be turned off

boyzo wrote:

It seems I am trying to do some not so ordinary configuration, but this might help someone else as well.

Bojan

I have 5i20 & 7i52 (without S for now, I will try to mod it to S-version) & Granite VSD-E & "their" BLCD servos so I'm really keen to follow your progress. Any updates?

Ekke wrote:

I have 5i20 & 7i52 (without S for now, I will try to mod it to S-version) & Granite VSD-E & "their" BLCD servos so I'm really keen to follow your progress. Any updates?

Following guidelines from this forum (thanks to all help from Andy, Cmorley and PCW ) I was able to get to the point where I am OK for now. I need to do real test on the machine. The following is my definitions:

setp hm2_5i20.0.pwmgen.02.scale 480

setp scale.y.offset -240.2 With this I get 0.000 standstill position at drive enable, with -240 always some offset (0.003). Drive is almost steel, flicker on 0.000 - 0.001 every several seconds.

scale.y.gain - not sure what value to put there.

P=6, D=0, I=0, FF0, FF1 and FF2 all zero. It was suggested that FF1 needs to be set to 1, but with any value in FF1 I get following eror.

Other parameters:

FERROR = 1.3
MIN_FERROR = 0.1
MAX_VELOCITY = 180.00
MAX_ACCELERATION = 1000.00

I am not happy with high rapid following error, also min ferror seems high, but checking it with G1 Y500 F1800 keep ferror below 0,05.