Joint following error

[Gads]

help..

acquired a laptop with more mem and speed and setup emc on this all seemed ok untill i started doing some long rapids and system sets error and looses steps. have double checked latency approx 14000. the rest of the system less the laptop was running fine on old 450mhz desktop prior to swap.
getting joint follow errors when rapiding for any distance. I have changed vel. and acc. in stepconfig.ini played with latency nothing.
can these settings be changed globaly in my ini file or run stepconfig.
I ask because rapids dont sound the same as what i get when testing in the stepconfig wizard. system runs everything program wise.

stepper system
ubuntu 6.06
emc 2.2.3

Thanks gads

[Big John T]

Laptops are not for real time...

John

[Ryobiguy]

Originally Posted by Big John T Laptops are not for real time...

Yeah probably, but... If the latency is 14000, does it matter that it's a laptop? That's a direct measurement of just how real-time it is.

Assuming you're using a parallel port, does your laptop have a weaker voltage on the pins? Maybe with a weaker signal the motor driver inputs are picking up more noise when the motors are moving quickly.
Just a wild guess to check the electrical side of things.

[Big John T]

Originally Posted by Ryobiguy Yeah probably, but... If the latency is 14000, does it matter that it's a laptop? That's a direct measurement of just how real-time it is. Assuming you're using a parallel port, does your laptop have a weaker voltage on the pins? Maybe with a weaker signal the motor driver inputs are picking up more noise when the motors are moving quickly. Just a wild guess to check the electrical side of things.

The problem with laptops is not the latency it's the nasty habit they have of shutting down and interrupting the processing which gives you missed steps etc...

John