which card to buy

More
23 Aug 2017 01:19 #97902 by Jorgefv
Replied by Jorgefv on topic which card to buy
I was so busy with my regular job that I left this project aside for a while but I'm back
I don't know witch kind of cable do I need to use, documentation is not so clear, but for what I understand regular straight cable should work for the smart serial cards.

also I was finally able to connect the encoders to the 7i48 all the encoders work great, all of them are differential encoders, I've not tested all of them at once because I'm not using the external 5v supply

but I've got a really serious issue connecting the analog voltage to the indramat tdm servo drive whenever I enable the outputs the servo just shakes violently I have tried on the X axis which is the longest and also the strongest.

there are 4 terminals e1 and e2 are differential inputs and those are the ones that were connected to the original num750 controller and there are also the e3 and e4 which are summing inputs respect to the input 0vm, I tried connecting the output of the mesa 7i48 to e1 and e2 and between e3 and 0vm also e4 and 0vm always with the same result

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

More
23 Aug 2017 12:42 #97920 by andypugh
Replied by andypugh on topic which card to buy

but I've got a really serious issue connecting the analog voltage to the indramat tdm servo drive whenever I enable the outputs the servo just shakes violently I have tried on the X axis which is the longest and also the strongest.


Have you done any PID tuning? It sounds like you need to make the P-gain _much_ smaller and zero-out the others for the present, then start tuning.

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

More
23 Aug 2017 12:47 #97921 by Jorgefv
Replied by Jorgefv on topic which card to buy
I have not done any tuning but I have not sent any voltage to the servo yet, just enabled the output which is supposed to be 0v to the inputs and the servo should not move at this stage
it may be because I'm not feeding the 5 volts to the 7i48? I'm just using the power from the flat cable.

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

More
23 Aug 2017 12:50 #97923 by andypugh
Replied by andypugh on topic which card to buy
If the analogue inputs are not connected then they might be responding to random electrical noise.
What happens if you short the input with a wire?

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

More
23 Aug 2017 13:02 #97926 by Jorgefv
Replied by Jorgefv on topic which card to buy
I tried shorting the servo input with a wire and it just stay there, the random movement only happens when I enable the output on the 7i48, that servo is so strong that shakes the whole machine.
I have not tried shorting the output when connected to the mesa card but I suppose the result would be the same the servo just not moving.

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

More
23 Aug 2017 13:04 #97928 by PCW
Replied by PCW on topic which card to buy
Are the PWM generators set to mode 2? if not you will get really weird results

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

More
23 Aug 2017 15:06 #97933 by Jorgefv
Replied by Jorgefv on topic which card to buy
this is from my hal file
# ---PWM Generator signals/setup---

setp hm2_5i24.0.pwmgen.00.output-type 2
setp hm2_5i24.0.pwmgen.00.scale [AXIS_0]OUTPUT_SCALE

net x-output => hm2_5i24.0.pwmgen.00.value
net x-pos-cmd axis.0.motor-pos-cmd
net x-enable axis.0.amp-enable-out => hm2_5i24.0.pwmgen.00.enable

and the pwm frequencies
setp hm2_5i24.0.pwmgen.pwm_frequency 20000
setp hm2_5i24.0.pwmgen.pdm_frequency 6000000
setp hm2_5i24.0.watchdog.timeout_ns 5000000

it only happens whenever I enable the outputs from the 7i48
I will try now connecting with an external stable 5v supply to see if that is the problem.

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

More
23 Aug 2017 18:44 #97942 by PCW
Replied by PCW on topic which card to buy
Also you might start with PID === 0,0,0 so you dont get any output from the 7I48 when you first start

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

More
23 Aug 2017 20:17 #97948 by Jorgefv
Replied by Jorgefv on topic which card to buy
I tried with the 5v from an external supply and there is not tremble anymore, but when I try to send a voltage to the servo it seems that it tries to move but without success, I tried it with the servo connected and the voltage to the servo is like 500mV but I tried without the servo connected and I got voltages of 7 or even 10v it depends on the value I set on the AXIS interface.
I tough I got the encoder backwards but i don't know if that could be the cause the encoder works great moving the axis manually

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

More
23 Aug 2017 20:29 #97949 by Jorgefv
Replied by Jorgefv on topic which card to buy
I also tried with a 1.5v AA battery and the servo moves really well

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

Moderators: cncbasher
Time to create page: 0.119 seconds
Powered by Kunena Forum