On Tue, 19 Nov 2024, Viesturs L?cis wrote:
Date: Tue, 19 Nov 2024 19:16:18 +0200 From: "[UTF-8] Viesturs L?cis" <viesturs.la...@gmail.com> Reply-To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Subject: [Emc-users] 2 questions (probably) for PCWHello! First thing is that there is Commander CD750 VFD for the spindle motor that I have (almost) under control with 2 output pins on 7i37 board and an analog output of 7i36 board. The thing is that I do not understand why is the analog output voltage fluctuating. I did a short video here: https://www.youtube.com/shorts/no8-CHsCggc What I have there is pwmgen scale set to 100 and value at 30 so that should be 3V on the analog output. There is slightly more. With pwmgen value equal to 0 I still have 0.3V so I would gladly fix that offset but have no idea how. But the main problem is the fluctuation because then VFD also is adjusting the motor speed. For demonstration purposes I did turn the spindle on and it can be heard easily that motor speed is not steady. Those numbers on VFD are output frequency as an additional indication that input voltage is fluctuating. I would appreciate any ideas where to look further.
I would check the 7I36 output voltage when disconnected from the VFD. If that seems ok, it may be a VFD EMI or grounding issue. This might require a line filter on the VFD, a common mode choke on the VFD wired going to the motor, or possibly a common mode coke on the analog signal/gnd wires going to the drive
The second question is about Yaskawa encoders and decoding rotor position from C channel pulses as described here: https://forum.linuxcnc.org/27-driver-boards/53321-yaskawa-incremental-encoder-and-mesa-7i48?start=0#305997 Is it possible to implement it? So far I have been circumventing it by keeping the old drives in the cabinet for treating the encoder signal and export "standard" ABZ signal for LinuxCNC, but now the thing is that I have a first case of the encoder signal output being unreadible any more. Viesturs
Is there a complete specification of the C signal protocol?
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Peter Wallace Mesa Electronics _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
