My 7i76e Connection Sheet

Hi
I'm new to the forum and also new with Linuxcnc. But I managed to install a MESA 7i76e in Linuxcnc 2.7. My question now concerns the following question: Can I connect directly the output signal of a 24V 3-wire NPN Omron EE-SX670A (NPN) to 5V logic (Index hookup of the Encoder part on TB 3). And can I also use the output signal of a second NPN Omron EE-SX670A with the encoder connector A? The signal of a perforated disc with 12 holes is read off. - Thank you very much for your help!

Gommiswald wrote: Hi
I'm new to the forum and also new with Linuxcnc. But I managed to install a MESA 7i76e in Linuxcnc 2.7. My question now concerns the following question: Can I connect directly the output signal of a 24V 3-wire NPN Omron EE-SX670A (NPN) to 5V logic (Index hookup of the Encoder part on TB 3). And can I also use the output signal of a second NPN Omron EE-SX670A with the encoder connector A? The signal of a perforated disc with 12 holes is read off. - Thank you very much for your help!

Double post !
Never connect 24V parts to 5V parts without voltage dividers, they are simple stuff made by 2 resistors in case of signaling.

This is a very helpful guide for getting started -- thank you for it! Can anyone explain how I would connect/configure normally open NPN prox sensors correctly? I realize they are not the optimal choice, but they are what I'm currently stuck with. I'm powering them at 24v, directly from the power suppl. They push +24v to the input pins when not activated then when activated they flip to ground. Is this OK?

Thanks again.

Typically NPN proximity switches would need a relatively stiff pullup resistor (say 2K 1/2W) to 24V
to work with the 7I76E's sinking inputs (because a bare NPN output can only sink current to ground)

If they output +24V into the 7I76E inputs wihout added components,
it likely means they are either not NPN sensors, or they have built in
pullup resistors or push-pull outputs.

Thanks for the reply. I have 8 of the sensors in the pic attached (min/max on every joint of a gantry router). They are apparently acting as they are designed, as confirmed by some Googling and YouTube demos of the product. I have some 2k/1w resistors in the parts bin, but lacking any direct experience from others using this type with the 7i76e I'm concerned about unforeseen consequences. I'm learning as I go.

If I've just got the wrong product, I can fall on my sword and buy new PNPs -- but if there is a way to make it work with what I've got, that would be preferable. I welcome any informed opinions -- if I should not bother wasting my time with a patchwork mish-mash, don't be afraid to say so

I made the same mistake and use the pull up resistors as PCW has said and they work fine. You can see the resistors spanning between the output and +24V in this pic.

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