No spindle stopped signal from VFD

Hi,
I'm having issues with the spindle stopped signal from the VFD on a Biesse Rover 322 retrofit.
VFD is a Commander CD-series, with a spindle stopped signal configured on Terminal A0 (see attachment for details). I suspect the output to be bruned, as it gives 24V out, no matter the state of the VFD (ready, accelerating, at speeds, decelerating, stopped).

 

Original config of the machine uses this output for spindle stopped signal, and RS-485 for speed and other commands. As the serial link uses ANSI x3.28 (not modbus) I've not been able to get it running with LinuxCNC. Hence I've been left with analog control of the VFD.

Reading the 0-10 volt output from the VFD with analog in on MESA hardware gives me 2.3 to 6.1 volts with lots of noise. Tried several different cables and shielding strategies without luck.

Would appreciate any and all input on following:

1. Has there been any work done on implementing ANSI x3.28 over RS-485?
2. What's involved in writing a driver to get the serial interface working via USB dongle?
3. Can the output terminal on the VFD be repaired?
4. How to reliably read the 0-10 volt speed output from VFD

Kind regards TomE.

the open collector output drives a relay as per the original configuration of the machine. relay ties furter into the hardware, likely providing hard-wired safety logic of sorts. Also connection from relay to IO on MESA.
I've tested reading IO from relay and mulimeter at VFD terminals both with and without relay connected to VFD.

No spindle ecoder (woodworking machine).

Thanks for place to start wrt driver development. Would be interesting as ways of contributing to community in addition to solving my problem. Decided to pay my way out of the problem by ordering replacement VFD. Hope I won't regret it...

hi.
i'm new here and in automation.
i have an biesse 322 and want to ungrade it.
please if you can help me give an answer, i want to have a large discussion in privat
thanks

of course, linux cnc will be the software but i am scared by the dimensions of the electric schemes

To close this post: I eventually gave up on the original VFD and opted to buy a new Delta MS300 that has MODBUS communication. After some fooling around I got it up and running with proper spindle stopped, spindle at speed +++ signals. All well.

Top tip to anyone following the same path: MB2HAL does not support MODBUS ASCII (default on the drive). Need to change drive to MODBUS RTU. Would have saved me a couple of days of hairloss if I knew when starting out.