Humidity transmitter wiring help

Hi,

I want to connect a RH transmitter on a 1746-NI8 card on my SLC500.

I'm just a little bit confused about the wiring
Here's what I have :


If I understand I need to connect :

• +24VDC on the power connecter on the RH transmitter (coming from 24VDC pôwer supply for exemple)
• Wire from OUT on the RH transmitter to the Input+ on my 1746-NI8 card
• -24VDC to the INPUT- connecter on my 1746-NI8
• Make sure that my input is in 4-20mA mode. (DONE)

I think that part is clrear, but is the 1746-NI8 card will support 24 VDC??? I connect the RH transmitter like that, I will have 24 VDC on the OUT connecter on the transmitter and then connected on the SLC card.

Thanks
Martin.

yeah you have it, that will work. i am not sure about your question regarding the support of 24v DC? this type of card can handle that voltage level.

cheers

myles

Sounds like your humidity transmitter sends a signal only when its in range if it was sending analog data on the output the range would not be 24 vdc standard ranges include 4-20 ma 0 to 10 volts -5 to +5
(-20 to +20 -10 vdc to +10 vDC) these are the ranges on the 1746 NI4 card
acceptable ranges are usually written on the card I don't have an NI8 version of card to check that but I don't beleieve I've ever come across a 24 vDC analog range

http://control.etfbl.net/real/174668.pdf

above is a link to the manual for this card page 3-8 has examples of the type of two wire transmitter you are using. this is a very common practice.

cool guess I learned something new today

Thank you very much for your quik response!

Really appreciated. I will connect my sensor today

Thanks again
Have a nice day
Martin.