Hello! I am stuck with the plasma machine that has 7i96 board and also THCAD board. My biggest issue is getting THC module to work. I have managed to get the encoder module to receive pulses from THCAD board and to count them. Here are the encoder settings: https://www.picpasteplus.com/v.php?i=b5f8366a2e The problem is that THCAD board is not sending any pulses with the frequency division jumper set at 1/1. In that case the rawcounts pin of encoder module remains at 1. If I move the jumper to 1/32, rawcounts pin immediately starts to increase and the encoder velocity is approximately -120. The thing is that I was expecting the value to be 120. But why is it NEGATIVE?!? I tried setting encoder scale value to be negative. It fixes the issue of velocity being negative. Nex problem with THCAD card is that if I fire the plasma and it creates the arc, encoder velocity decreases. Yes, it gets smaller. Approximate value is 96 for that particular torch height I have set. I watched both velocity and position pins of the encoder module. Position pin was increasing, so the pulses were still coming and it was not a glitch of a "frozen" value at velocity pin. My way of circumventing this is negative value for thc.scale_offset parameter. Then with negative encoder velocity value, which is decreasing as the plasma starts and negative offset I get positive voltage value in THC module.
And then there is a minor problem with 7i96 board: https://www.picpasteplus.com/v.php?i=f609e19c95 This error was triggered a minute or two after I launched the LinuxCNC. Is that subject to poor config of the system? PC has mini-ITX board with dualcore Celeron CPU and 4 gab of RAM. Should be plenty of power for LinuxCNC but apparently I am wrong. The thing is that after this error HAL pin values were "frozen" and encoder velocity pin was showing approximately 120 while the position pin was also frozen and did not change. Second thing is that I have to use an existing plasma source that they already have - "Telwin enterprise plasma 160 hf", which is meant for manual cutting. So there are 2 challenges - get the plasma voltage and arc-ok signal. Does anybody happen to know, if the controller board of this machine has dedicated outputs for these 2 things? I have connected 2 wires to plasma ground and torch cables respectively and connected them to THCAD board. I hope that it would work and not cause too much of EMF noise. Cable is shielded, shield is connected to ground at a single point with all the other cable shields. How do I obtain arc-ok signal? Can I do it in HAL by watching plasma voltage and trying to assume that it is ok, when voltage drops below some preset treshold? Or is there a doable way to take a signal that would drive a relay to trigger input of 7i96? Viesturs _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
