Tying together negitive wires for relay modules

[garrettw]

Hello,

I recently picked up a G3 and i'm starting to wire up a new control box using it. I'm using a 12v power supply to power the Masso and have picked up a opto-isolated relay module to use on my outputs. The relay module itself requires 5v power so it is powered by its own separate 5v power supply.

My question is when triggering the Masso's TTL outputs to 5v+ high. Is it safe for me to run a wire from the negative/ground terminal on the masso (between the outputs on the bottom) to my seperate 5v power supply negitive terminal blocks (and so its also tied to the relay module)? It would seem if I don't tie these together I don't have a complete circuit for the 5v ttl signal but I just wanted to make sure this was considered safe to do?

Thanks

 

[breezy]

Garrett,

You have the right idea but tie the -ves together at the power supplies. Don't use the negatives on the MASSO, if something goes wrong with the PS you could damage your G3.

Regards,

Arie.

 

[garrettw]

haha, I'm not sure why I didn't think to just do it at the power supplies.

Glad to hear that should work fine, thanks for the help!