Thanks guys,

Definitely on the volts, this meter only has three sockets - V/mA, Com, 10A and i only used the Com and V/mA ones 99% of the time.

I can't see lead capacitance having any effect here, surely it should be a measurable 0 to 10v Dc signal going to the VFD?

I know 4-20mA can be a pain to measure sometimes unless its loaded properly but 0-10v?