On Mon, Apr 06, 2009 at 04:09:22PM +1200, Jason Xu wrote: > I am a new user of Ethercat device, and when I use BeckHoff EL3102 analog > input device in an experiment (by following the example c code in mini and > RTAI of document "ethercat-1.4.0-rc3"), I find out that if I keep the > scan-cycle at 1 hz, I can access the Sdo data successfully, and read the > value of analog in. However, if I put the Read_sdo() in a higher scan-cycle > (e.g. 1000hz), it always shows EC_SDO_REQUEST_BUSY status.
please use PDO exchange for rates like 1 kHz and higher. SDO transfers are not designed for exchange rates like that. SDOs are for asynchronous access, PDOs for synchronous (cyclic) access. > About two years ago, someone asked a question about read_sdo in realtime. At > that time, the answer was No. Is that still the case now? If so, is there a > way to read a value of analog_in in real time? Yes, via PDO exchange. ;-) -- Best regards, Florian Pose http://etherlab.org _______________________________________________ etherlab-users mailing list [email protected] http://lists.etherlab.org/mailman/listinfo/etherlab-users
