Masso SC5/SC7 no voltage

Spindle/VFD (Aftermarket)
1

So I got everything wired up, but before I connected my spindle control lines, I decided I wanted to confirm voltages and test my IOT relay for the liquid cooling.

I turned on CW on the Masso, can see the output is active high. I can see 3.3v on SC2, but no voltage on SC5. Similarly with CCW I can see 3.3v on SC3, but no voltage on SC7.

Do you have to do anything special to get voltage on the opto-coupled outputs (IE: external power to other pins to provide voltage to the opto’s)? I’d prefer to use them, but I get no voltage. Any thoughts?

In addition to sending CW line to the VFD, I am also using an isolated IOT Relay that only requires 0.2mA constant current, so no need for a diode if I use the non-opto outputs, but I am curious why there is no voltage to the opto outputs.

2

Nevermind, took a bit of digging, but found the information. The opto’s work as an external relay, sourcing the voltage from the VFD, which I didn’t have powered up during the testing.

I should still be able to connect my IOT relay to the non-opto, and the VFD through the opto, makes sense now.

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3

Hey Shane,

an optocoupler by itself is no source of voltage, it is like a electronically controlled switch. Usually you take the voltage separately and lead them through them. You could use the +DC supplied by the Controller and then switch something this way.

See also

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