1771- ife/b

Hi Guys,

i am trying a loop powered sensor with 4-20mA to work on an allen brad 1771-IFE/B input card but not working correctly, i have taken a 24v supply to sensor and back to card term channel + and out channel - to 0v, the card is set up for diff, i was wondering also if change to single end would rectify the problem or be the same, the sensor is two wire and terminals 20 21 on the card are linked to 0v

What terminals are you connecting the sensor to?

Make sure the jumpers are set for current not voltage for the channel you are using. ( double check)

Have you checked the current with a meter in series with the card?

If using differential there is no need to connect the power supply to terminals 20 and 21. ( see drawing)



See pdf below for drawing.

hi, thanks for the reply, the sensor connections are +24v and output or signal, i have the same sensor on flex IO and works fine, i have opened the card and its definitely set for diff current one horizontal link then two vertical links and so on, i have put ammeter on it and getting 12 mA with no input to sensor and there are 4 sensors all the same incorrect mA signal back and 4 on flex IO working correctly, the main thing that was bothering me was in the drawing the channel terminals are + term 1 and - for terminal 2 but there is no voltage on terminal 1 and acting as return to 0v

but there is no voltage on terminal 1 and acting as return to 0v

Click to expand...

Its not clear to me what the question is.

With 12ma flowing thru the circuit putting a meter across terminals 1 and 2 you should read 3 volts.

I will mention it just in case, you are aware the jumper placement is different in a series B card as apposed to a series C. Make sure you have the proper manual.

https://www.google.com/url?sa=t&rct...82A7sPTRxbJyRce3w&sig2=7UXAWtzIZPyLSu_CebQa3Q

Can you post the program its .RSP file ( zip it first) and tell us the slot the card is in?

and exactly which terminal numbers you're connecting to ...

Hi there, i have attached the url for the sensor, if you look at the bottom of page 4 there is a diagram, the 24vdc is connected from a panel 24vdc source and the - terminal on sensor goes to terminal 1 on card and terminal 2 on card goes to 0v, hope the diagram helps explain better than me

http://docs-europe.electrocomponents.com/webdocs/0526/0900766b80526eb1.pdf

Unless I'm missing something that should work ( maybe someone else can spot something). What are you reading with a volt meter across terminals 1 and 2 of the analog card? (12ma ( you stated above) should give you 3 volts)

not a work atm but will check and get back to the forum, thanks for the posts