On 02/08/2016 09:01 PM, Nicklas Karlsson wrote: >> I agree with the sentiment that it is less than ideal to have something >> that certainly has a local microprocessor that then creates an analog out >> which you then read in. It's a lossy channel and subject to any number of >> problems. That assumes you have the software skills and documentation >> necessary to control the beast. >> IMO, lacking a detailed description of the modbus commands, the digital >> interface is best used as a door stop. > I would agree digital modbus should be the first but do not forget > the bits per second needed. > > 115200 bits/second, 1kHz servo loop => 115.2 bits per servo loop > equal to around 14 bytes per servo loop excluding overhead then > RS-485 is probably half duplex.
You may need a higher throughput to compensate for round-trip-delay too (group-delay in analog terms). Also, rs485 (multi-drop, half-duplex) may be inferior to rs422 (point-to-point, full-duplex). The Baudrate of the channel is not limited to 115k2, but can easily go into multi-megabit. It is a question of matching requirements with the correct hardware and software. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
