Multi-slot TDMA Configuration in RTnet

Jan Kiszka jan.kiszka at siemens.com
Wed Sep 2 09:03:15 CEST 2020


On 01.09.20 19:08, Lakshmi Dhanaraj via Xenomai wrote:
> Hi,
> 
> My System is configured with Xenomai-3.0.5 on Linux-4.9.38 kernel under
> Ubuntu 18.04.1 LTS. I am using I210 Ethernet Controller with the capability
> of 1Gbps.
> 
> Configured Master and Slave TDMA slot 0 with offset 0 and 400 respectively
> along with a cycle period of 1000 us. For Single-slot(Slot-0), it is
> working fine.
> 
> To configure multiple slots at the slave side, set the offsets 200,400 and
> 600 for rteth0 for slot-0,1 and 2. Monitored the data transmission at
> Wireshark, the packet is transferred once in each cycle period with size of
> 1470 bytes.
> 
> In the calibration request frame, only slot 0 is shown. Does it seem only
> the data transmission occurs from slot-0 only at every cycle period?.How to
> check about slot information in the data packets? How to configure multiple
> slots between a master and a slave?
> 
> 
> Waiting for the reply at earliest.
> 

Did you see
https://gitlab.denx.de/Xenomai/xenomai/-/blob/master/kernel/drivers/net/doc/README.rtmac
already?

One thing I had to read up myself again (wrote that 15 years or so
ago...) is how you can address a specific slot with a transmission from
an application. That works via setting RTNET_RTIOC_XMITPARAMS and
SOCK_XMIT_PARAMS, see also
https://gitlab.denx.de/Xenomai/xenomai/-/blob/master/include/rtdm/uapi/net.h.

Jan

-- 
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux



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