A-M-C A12A100 Servo Drive with SouthWestern Ind ProtoTrak Plus

PCW, Many thanks. I can get 60"/min feed rate. As per this pic in an earlier trace.

link:https://forum.linuxcnc.org/media/kunena/attachments/21712/p20ff1-.0001ff2-.23feed60.png

Granted P is only 20.

All encoder stuff & 7i77 board is brand new, I should be looking for wire that is cut or poor connection at the 7i77 or other locations. Just thinking where to start.

many thanks

I suspect some basic hardware setup issue
If you are running the drives in torque mode
(which us the same as current mode)
do you have the drives current limit
and current scaling set to match your motors?
It seems very weak

PCW, Many thanks for your help. The data sheet (full copy in 1st post) has this statement for POT 2, turning CW increases limit:

"Current limit. It adjusts both continuous and peak current limit
while maintaining their ratio."

I have this full CW, so that increases the limit. So that means the limit is too large? and really want full CCW, so no limit?

many thanks

Edit: I see this as a sw3-10 setting: I want Deadband, correct? I do not recall setting this at all.

"Deadband activation. When deadband is active, input commands close
to zero in both directions will result in zero output.
OFF by default"

many thanks

You would not want deadband

You would want to set the current scaling in the drive
so that the full scale current (at 10V in)
equals the motors peak current rating

PCW, Thanks for all your help. I have reviewed set up, POT 3 is full CW so the full drive output available for a 10V command is available. POT 2 full CW for motor "rated current" 6.25 amp.; POT 1 full CCW for "current mode".

Could a failed 5i25 card be responsible for problems displayed? This is only component other than motors and power supply.

many thanks

new2linux wrote:

PCW, Thanks for all your help. I have reviewed set up, POT 3 is full CW so the full drive output available for a 10V command is available. POT 2 full CW for motor "rated current" 6.25 amp.; POT 1 full CCW for "current mode".

Could a failed 5i25 card be responsible for problems displayed? This is only component other than motors and power supply.

many thanks

No, a failed 5I25 could not cause this issue

You can check that the analog +-10V outputs function properly by first disabling the drives
then launching LinuxCNC and running these halcmd commands in a terminal:

halcmd -kf
halcmd: delsig x-output
halcmd: delsig x-enable
halcmd: setp hm2_5i25.0.7i77.0.1.analogena true
halcmd: setp hm2_5i25.0.7i77.0.1.analogout0 10
(check for +10V on 7I77 analog out 0)
halcmd: setp hm2_5i25.0.7i77.0.1.analogout0 -10
(check for +10V on 7I77 analog out 0)

note that the "halcmd:" is a prompt printed by halcmd, not something you should type

Do you have your motor specs? 6.25 A peak sounds quite low

PCW many thanks. This is link to motor data:

forum.linuxcnc.org/media/kunena/attachme...14969_2021-02-05.pdf

See the 3nd line in data box in the center of page.

I will try the halcmd tomorrow.
Many thanks!

Edit: To confirm, at (TB5) pin 4 (AOUT0) use meter looking for 10v. High voltage to motors, unplug back of panel box, but leave the encoders connected.

PCW, Many thanks for your help! After launching LinuxCNC (the usual way) and running these halcmd commands (at terminal) per your suggestion the meter readings are -10v after this line (halcmd: setp hm2_5i25.0.7i77.0.1.analogout0 10) and "the same, -10v" reading after (halcmd: setp hm2_5i25.0.7i77.0.1.analogout0 -10). There was no meter reading before this test.

Many thanks!

OK if you read -10V in both cases there probably a measurement mistake, but 10V means the 7I77 is OK. The question is now why the drive is so sluggish with a full current command.

One thing is that you are only supplying about 1/3 of the peak current required by your motors (Rule of thumb is that peak motor current is about 3X the continuous rating so for your 6.25 A continuous duty motor, about 19A of peak current would be needed to get full performance)

That said, 6A should do better than you have currently. Have you checked the motor power supply voltage?

PCW, Many thanks! The DC volts going to the driver from power supply is 37.9.

thanks!

Edit: PCW, thanks for your help. I pondered this from your prior post "OK if you read -10V in both cases there probably a measurement mistake,". Should I of measured between the (TB5) pins 3 & 4, to get this correct? many thanks!