Mixed I/O voltages

Does it matter if you use mixed I/O voltages in the system or is it best to make everything 24V?

If so what is the best way to make 5v encoders and other sensors run at 24v?

I'm not the one to answer your question but it maybe helpful anyway to specify what electronics you're using.

I was just going to ask this question. I have some 5v iand 24v input devices.

My impression from the manual is as long as the "low" signal is below the threshold and you don't exceed the maximum, it will be happy. Anyone confirm this is correct?

For outputs, it will spit out 24v though.

If you have 5V encoders I would use them as-is and do limit switches and misc sensing at 24V

24V encoders are relatively uncommon and usually slow

It was more of a general question about managing the different volatges of I/O


for example do I need to boost 5v sensors to 24v to improve immunity

For things like proximity sensors 12/24V makes more sense

Note that changing differential 5V encoder signals to 24V
single ended signals will _lower_ the noise immunity

One of my spindles has a 24v single ended encoder. but its "just" a tacho, not intended for any form of positioning.

For 5V I am more thinking of IO off a micro controller in cases where I don't want to or can't talk to it via serial. This would be inputs on the mesa only, used at the same time as other 24v inputs like limits and buttons / switches.

Ross77 wrote:

Does it matter if you use mixed I/O voltages in the system or is it best to make everything 24V?

If so what is the best way to make 5v encoders and other sensors run at 24v?

Depends on what boards you are using. I have a big machine with 5vdc, 12vdc and 24vdc.

Some mesa board you can split the voltage for inputs. It is best to keep i/o the same voltage and 5v for encoders.

The noise window for 5v is more susceptible to having issues.

That's just my opinion.

Thanks for the replies.
I potentially have a mix of sensor voltages as I use 5v IR slot sensors for homing and ATC positioning etc and 24v on the limits.


I'm trying out work out if I need to get rid of the 5v sensors or just boost them at source

I was planning to use 24v sensors on the 7i76 and then put the 5v sensors on the 7i77 but wasn't sure if that was a good idea and everything should be 24v

Ross77 wrote:

Thanks for the replies.
I potentially have a mix of sensor voltages as I use 5v IR slot sensors for homing and ATC positioning etc and 24v on the limits.


I'm trying out work out if I need to get rid of the 5v sensors or just boost them at source

I was planning to use 24v sensors on the 7i76 and then put the 5v sensors on the 7i77 but wasn't sure if that was a good idea and everything should be 24v

I would think it makes more sense to change out the sensors for 24v ones. Possibly save less headaches later.