> On 02/08/2016 07:01 PM, Dave Cole wrote: > >>> RS485 is two wire, half duplex. > >>> I think you have a RS422 connection that can run full duplex. > >>> I don't recognize the D and R pins?? Perhaps Data Ready and Request > >>> to Send ?? > >>> Those aren't normally required for RS422. > >> I am becoming increasingly tempted to forget the Modbus idea. > >> Analogue control is realtime, for one thing. > >> > >> Also, I can't find any documentation of the Lovato VE1 modbus > >> interface. No register numbers, and only the pinout info above. > > Unless you need to change drive parameters it might be a waste of time. > > > > Analog is easy. > > Analog is hard, very hard, if you want the same quality as the digital > equivalent. > > There is a reason why there is a strong trend for going digital, which > is primarily rooted in noise-immunity and signal recovery. > > An analog signal is, just like digital, bound by impedance of the > transmission line. However, a slight imbalance in digital is > recoverable, whereas an analog version will skew the result without > possibility of (correct) recovery. > > Noise in analog will reduce the effective resolution, whereas noise in > digital can be easily filtered and the resolution stays constant. > > Analog signals cannot be isolated easily and trying so results in > awkward non-linearities that need to be compensated. A digital signal is > easily isolated and does not require complex compensation.
Yes analog signals certainly have problems in particular with isolation barriers and noise but replacing with high resolution and bandwidth require quite a lot of bits per second. Nicklas Karlsson ------------------------------------------------------------------------------ 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
