Best to know the nature and details of the part the switch is interfacing to.
That is a PNP device so it is sourcing, the resultant interface would need to be able to sink.
Max.

 

I dont really understand Max?

 

 

I have just learned that the people before me had trialed this sensor http://ie.rs-online.com/web/p/ultra...43D3339392D35343738267374613D3339393534373826
and it worked somewhat, the only problem was that the ultrasonic signal was picking up on the rotating shaft inside the vat and therefore they moved to the capactive type but this sensor is programmable like the other one http://ie.rs-online.com/web/p/products/0554667/ but yet the ultrasonic one is PNP and the Omron was NPN yet they BOTH still managed to work how is this i thought PNP couldnt work on NPN and vice versa. Even so i think the capactive programmable NPN should work for me??

 

Am I rift to think this?

 

the ultrasonic one is PNP and the Omron was NPN yet they BOTH still managed to work how is this

Whether the type is designated NPN or PNP may be immaterial (I've no practical experience with either type of sensor to know if there are industry standards for this), provided the option of NC or NO is available, which it seems to be with all the sensors you have linked to.
I envisage three possible sensor output examples as shown below :

Although A and B have PNP and NPN output transistors respectively they can both source current from the 24V rail. Depending how the output stages are driven they could act as NC or NO.

 

Hi guys just giving an update on the control.

I have installed the following sensor http://ie.rs-online.com/web/p/capac...3743D3535342D363637267374613D3035353436363726

The problem is that this wouldnt switch until i put a 24v dc realy in to switch it so what i did was took the trigger signal to turn on the relay and used the NO of the relay to switch the other side of the trigger then it worked. I tried to duplicate this on the other hopper which is switched the exact same way but it wouldnt work all circuitry is the same as is the relay the same i took this sensor out and put this original sensor it and it is working fine
http://ie.rs-online.com/web/p/capacitive-proximity-sensors/7449929/

i just dont understand why one side of this will work on the first sensor and relay but not on the other. I'm guessing i needed to put the realy in in the first place because i maybe wasnt getting enough amperage to switch the input? as i said its working with two different sensors and the realy but im confused as to why it is operating like this