+-10v setup 7i97 & .ini

More
10 Nov 2024 22:04 #314218 by Sziggy_NC
Hi all,
I was trying to follow tommylight's guide on servo tuning, but once I hook up the +-10v the motor jumps 0.010 on enable. Checking with a multimeter I am able to see 10v appear when I enable the machine. The measured pins are 3 & 4 on TB3 of a 7i97T. The manual shows 3 as GND and 4 as AOUT0.
      Are these pins the ones I should be useing for +-10v?
I have attached my hal and ini files. I would not be supprised if the problem is in my ini file. 
I am unsure of how to determine what values to use for MAX_VELOCITY, MAX_ACCELERATION, and OUTPUT_SCALE. I have tried different combinations of values without any luck. I have tried reading the docs and reading through all the forum posts I could find on those subjects.
     Could improper values for these or other variables cause the behavior I am seeing?
Thank you for your time.
Attachments:

Please Log in or Create an account to join the conversation.

More
10 Nov 2024 22:45 #314220 by PCW
Replied by PCW on topic +-10v setup 7i97 & .ini
Those are the correct output pins
 The MAX_VELOCITY and MAX_ACCEL
Are the physical maximum velocitys (in inches per second on inch machines)
and maximum acceleration in IPS^2 (typically 5 or 10 x the IPS value)

Note that on a first setup you may have the feedback reversed so you get a runaway
if the encoders are reading in the proper direction and scaled properly you can reverse the feedback by
changing the sign of OUTPUT_SCALE

 

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 01:21 - 14 Nov 2024 23:03 #314222 by Sziggy_NC
Replied by Sziggy_NC on topic +-10v setup 7i97 & .ini
Thank you for the confirmation and explanations. I have now corrected my velocity to match the rapid speed this machine is supposed to achieve.
In my case the rapid ipm is 944 so inch per sec would be 15.733 ips = 944 / 60
For acceleration I will try with it at 5 times the velocity to start with. 5 x 15.733 ips = 78.6667 ips which becomes 1.3111 ips^2 = 78.6667 / 60 

The encoders are reading in the proper direction. Measurements with a dial indicator match up with the DRO when moving the axis by hand.
Last edit: 14 Nov 2024 23:03 by Sziggy_NC. Reason: Correcting my bad math.

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 01:32 #314223 by Sziggy_NC
Replied by Sziggy_NC on topic +-10v setup 7i97 & .ini
After more searching about Output_Scale, I have set it to 10 since it is a +-10v system. I also changed my ANALOG_MIN_LIMIT to be OUTPUT_MIN_LIMIT = -10 & same for max limit now it is OUTPUT_MAX_LIMIT = 10.

I will give these changes a shot in the morning.

Thanks.

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 19:33 #314279 by Sziggy_NC
Replied by Sziggy_NC on topic +-10v setup 7i97 & .ini
While I am sure that the ini changes needed to be done, they didn't effect the behavior of the analog out pin.

The current behavior is that once F2 is pressed to enable linuxcnc I am measuring -10v across pins 3 & 4. From what I understand this should be 0v until I attempt to jog. Max speed in one direction is -10v and max speed in the other direction is +10v.

I think I have something wrong with my pwmgen.

From reading pwmgen in the docs, I came to the conclusion that for a +-10v servo I needed output-type 2. This is what I have been attempting to use.
Is this correct?

I have tried comparing my hal and ini files to the basic7i97 hal and ini. I'm at a loss for what to try next, but I will keep looking.

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 19:45 #314280 by PCW
Replied by PCW on topic +-10v setup 7i97 & .ini
PWM type must be 1
The following user(s) said Thank You: Sziggy_NC

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 20:15 #314282 by Sziggy_NC
Replied by Sziggy_NC on topic +-10v setup 7i97 & .ini
Thank you for correcting my mistake. The -10v is gone now.

I still have an issue though. Instead of jumping 0.0100in on enable it is now jumping 0.0015in. It is still enough to trigger a following error. I went ahead and checked voltages just to be sure. Before pressing F2 I am reading 0.008v after pressing F2 I am reading 0.010v. Is the voltage an issue?

Please Log in or Create an account to join the conversation.

More
11 Nov 2024 20:43 #314283 by PCW
Replied by PCW on topic +-10v setup 7i97 & .ini
You will need to widen the following error limits to be able to tune the joints.
The following user(s) said Thank You: Sziggy_NC

Please Log in or Create an account to join the conversation.

More
12 Nov 2024 16:10 #314329 by Sziggy_NC
Replied by Sziggy_NC on topic +-10v setup 7i97 & .ini
You are awesome! Thank you!

That was the final thing stopping me from continuing the retrofit.

After increasing the FERROR and MIN_FERROR in the ini I have tuned the X axis. I will get the Y and Z today.

Please Log in or Create an account to join the conversation.

Time to create page: 0.073 seconds
Powered by Kunena Forum