CAD CAM EDM DRO - Yahoo Group Archive

Question regarding VFD control input to MACH2

Posted by washcomp
on 2003-11-16 12:44:06 UTC
My latest spin on the control pendant I'm designing is to use the
remote control panel of the VFD as a componant on the face of the
pendant. This panel has switches for: FWD/REV, ON/OFF, speed UP/DOWN
as well as an LCD readout and should reduce the density of the
descrete switches on the panel.

MACH2 will be controlling the VFD through PWM, direction, etc.

Two Questions:
1) How much in the way of information about the settings of the
above switches should be sent to MACH2 as inputs (as well as the
drive) when the panel is used manually.

2) I'm open to any and all ideas about what signals I should pull
from MACH2 into the VFD. I'm assuming (please correct me if I'm
wrong) that the "Frequency (Step) to Voltage Convertor" circuit under
the files section of the CAD_CAM_EMC_DRO group is the best way to get
10 volts DC analog (uses a LM2907N chip), but I'm guessing I also
need rotational direction. What else should I be figuring on?

Are the switches on the remote panel generally "dry contact" and can
also send an input into a keyboard emulator if wired in parallel?

If the control panel cable is about 20 foot (7 meter) long, is it
important that it be shielded?

Is any one else further along this road?

Regards,
Jeff

Discussion Thread

washcomp 2003-11-16 12:44:06 UTC Question regarding VFD control input to MACH2