Andrew - You noted that you are using step/dir into servo drives - does it follow that your servo drives require those SPI interfaced encoders? In the servo drives I've encountered, if it has a step/dir mode, the drive is an intelligent one and handles the entire PID and feedback loop itself, meaning the encoder (or at least halls+) is fed directly to the servo drive.
Although I agree with Viesturs and recommend you go right to analog for your "production setup", it's quite acceptable to work with what you have first and get comfortable with it. In that regard (step/dir) it's unlikely that you'd be feeding back encoder data to EMC (you're treating the system like stepper motors). True, some have succeeded in getting steppers with encoders for closed-loop, although it's not the typical implementation. Does your drive by chance send out a buffered or recreated quadrature signal? Some drives do, as they are used for encoder following installations. If it does, you can likely keep the drive-encoder relationship as SPI (as the manufacturer intended?) and grab the quadrature signal coming out of the drive for EMC when you decided to convert to analog command mode...... On 7/3/2011 8:35 AM, [email protected] wrote: > Date: Sun, 3 Jul 2011 14:06:24 +0300 > From: Andrew<[email protected]> > Subject: [Emc-users] MESA 7i43 > To: "Enhanced Machine Controller (EMC)" > <[email protected]> > Message-ID: > <CAJZ=btnpfjyy8le7-easvaggnskonzhg43z7kqsla4a4gt_...@mail.gmail.com> > Content-Type: text/plain; charset=ISO-8859-1 > > Hi, > > I consider purchasing 7i43 board to control 6 servo drives. First in > step/dir, later in analog mode (with homemade PWM to analog > convertors). As long as I have SPI encoders, I'm not sure it is that > simple to connect them to EMC2 for analog servo mode, but I hope it's > possible. ------------------------------------------------------------------------------ All of the data generated in your IT infrastructure is seriously valuable. Why? It contains a definitive record of application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-d2d-c2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
