limit and home switche question for Mesa 7i77

Hello all I am in the final wiring phases of my VMC Retrofit and have a quick question regarding home and limit switches.

I have on hand a set to install which are:

Proximity type sensors, model SN04-N2: DC 10-30V, NPN NC, Three wire

but there are other type to use if the wiring setup is incorrect. I do know I want to use a normally closed switch based on searches and safety in the event a line breaks etc.. but I am a bit unsure on the type for correctly wiring to the 7i77 .. this has always been confusing to me and any assistance is greatly appreciated!.

Below are some attachment images with the types and their schematics. any help appreciated!

Chris

The 7I77 has active high inputs so works directly with PNP type sensors
Ideally PNP NC sensors should be used for limit switches since a broken
power or signal wire will cause a fault.

NPN sensors can be used but require a 1-2 k pullup resistor to +24V

Thank you PCW!! I was thinking the same thing, I appreciate the confirmation!! time to order some new switches!! :/ lol

Chris

I managed to get the TL-Q5 versions to work with my 7i76 no problem. BTW they are available on China ebay .

Andy,

I ordered the plastic ones, but they will be underneath the metal way covers which "should" keep them clean and dry.. at least until a way cover fails...

they are coming with 2m leads, not sure if they will be shielded wires though.. hopefully yes but I don't have my hopes up. the 2m should be enough length to get them safely outside the machining area for the next connections to the 7i77.

anyone else tried the plastic ones with success?

Thanks,

Chris

PCW wrote:

NPN sensors can be used but require a 1-2 k pullup resistor to +24V

ok, I did it. I put 2k2 pull up resistors to +12V. NPN sensors with NO.
and it does not work.
I measure the voltage at input contact 025. This is 10V when the contact is off and 0.3V when on.
but the logical state of the input contact does not change.always is off.
what else needs to be done?

it worked fine before with 5i20 and 7i37.

OK. I learned that pncconf wizard does not quite correctly call the pins.
In this case should be hm2_5i25.0.7i77.0.0.input-25-not.
And it works.