VFD and RPM readout

[kucharzb]

Hello,

can the VFD "read" the actual frequency/speed/rpm of the spindle. As an example - I setup the speed to 6000rpm, the display shows the corresponding Frequency (100Hz) - but lets assume that something exerts the braking force on the spindle (with hand/or just cutting heavily in a material) and the ACTUAL rpm/speed is lower than the one which was setup. Can the VFD show it? or it will only display the "expected" value? and to get the real frequency/speed of the spindle I would need an external tachometer?

The question is important for "wait for spindle" function - it needs to check if the spindle is REALLY working and not just pretend (or was blocked).

Thanks.

[charliem]

This Response is a little late,
Depending on your VFD you should be able to display RPM.
What VFD are you working with?