Paul Keeton wrote: > As I stated earlier - > > The mill currently has encoders on the motors. The issue is getting > the Fanuc drives existing on the machine at this time to work with EMC. The > drive requires an analog reference command signal. The drive also requires > an analog tach signal to operate correctly. It does a comparison between > VREF and TSA (tach) to calculate both direction and speed and adjusts the > drive operation accordingly. To my knowledge and based on the documentation > on this drive and motor it must operate in velocity mode. The encoder > signal(A,A/,B,B/,Z,Z/) currently is fed to the Fanuc 11M control and is > converted in the main control hardware to an analog signal that is sent to > the drive. This model drive does not accept PWM signal for VREF or > Quadrature for the tach. If you take the Fanuc control out of the picture > and install an EMC based control the drive will still require the tach > signal. The machine does not have scales, It does not have tachs, it does > not have encoders. These items can be installed if/when needed > My guess is the planetary gearboxes may make it hard to rig a tach to the motor. If these gearboxes are anti-backlash (there are several schemes to preload the gears to eliminate backlash) then you could put the tach on the leadscrew, and drive it by toothed belt. If the motor shaft is the integral pinion, then you won't have access to the motor shaft. if the motor drives the gearbox pinion through a coupling, then you ought to be able to rig a pulley to it for the tach.
So, you have a couple options, depending on the exact mechanical configuration. Rig tachs to the motor or leadscrew, or get a converter to generate the tach signal. Most velocity servo amps have a way to bypass the velocity error amp and feed the command signal into the torque loop. Often it is a switch, but it could be pulling a jumper. Then you would put the torque command in where the velocity error amp used to feed a signal. Jon ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
