living quite a long time in LinuxCNC world, I am excited to know about OpenCN and its features. I am especially interested in jerk limits for axes and probably joints in non-trivial kinematics.
I have several questions:
As I understand Intel e1000e is required to start on amd64 (x86) machine. Which adapter models are compatible and where to get one?
Would it be possible to run OpenCN using some Mesa card, like 6i25?
If talking about high-performance drives (100…200kHz) and servo loop rates 10kHz and above. What sets the limits? I met some drives having 200kHz servo rates. Maybe you know some hardware that would be compatible with OpenCN? Or at least theoretically, which high-performance drives could be used?
Thanks for you interest in OpenCN framework
Yes, the only NIC adaptator supported, for EtherCAT, is Intel e1000e. Base on the following page.
Linux* Base Driver for Intel® Gigabit Ethernet Network Connections, the supported cards are: Intel® PRO/1000 PCI-E
Currently, we do not add a support for Mesa card. We focus on the EtherCAT bus support
We did not make any max performance testing yet. We just make sure that the system works with EtherCAT bus set at 10Khz.
The main system limitation is the processing power. We are using Triamec TSD80e drives
Hope this helps.
regarding high en drives, it’s not only a question of the power electronics switching rate. Other important qualities are
- Servo loop rates (Triamec uses 100 kHz for current and position controllers)
- High PWM resolution
- low noise current measurement
- Oversampling and a good preprocessing of sin-cos encoders
I don’t know if there are better drives on the market compared to Triamec.
In principle other EtherCat drives should need relatively small modifications in order to operate with OpenCN.
However any other communication bus (e.g. Sercos) would need very important modifications. We recommend you to stay with EtherCat.
hope this helps.