HART Signal Conditioner 1

[lowdere]

I need to take a 4-20mA HART signal from a transmitter and send that input signal to directly to 3 different systems. I would like to use a signal conditioner, but the ones I know only give me one additional signal. Are there any out there that will give me two additional signals?

Or is it possible to cascade 2 signal conditioners to get my third signal? Will that degrade the HART signal??

Thanks,
Eric

 

[danw2]

Interesting question. I've never run a HART 4-20mA in series through 2 receivers, to say nothing of 3.

I can't answer your question, other than to point out that I have run into loop isolators which strip the HART off the 4-20mA because the loop isolator's low pass filter stripped the HART off before retransmission out the other side. I used a Phoenix Contact isolator specifically designed to pass the HART through.

Will a standard receiver's electronics behind the shunt resistor on the input filter the current signal enough to drop the HART below threshold? I don't know.

If this forum doesn't provide an answer, you might try the HARTbook forum at

http://www.thehartbook.com/forum/display_forum.asp?

fid=3#search

Dan

 

[addy1974]

hi,
I was recently informed by someone who is very well respected in the field of communications, that recent tests have shown that grounding screened cable at both ends instead of the one is the best method to reduce noise. Has anyone heard of this I'm just a run of the mill instrument/electrical guy and can't get my head round it.
Cheers
Addy

 

[itsmoked]

Hi addy1974 welcome to the forum!

Now a slap on the wrist. You should have started a new thread with your question as this is otherwise considered "Thread Hijacking" which generally causes much confusion.

Since I know your question will likely garner, possibly, lots of discussion let me suggest that you do this:

Start a new thread in <forum248> called "Grounding screened cable".

Copy and paste this question into that new post.

Then "redflag" this post yourself and comment "Sorry, accidental hijack". (We all do it occasionally.)

Then we can answer your question clearly without confusion.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[Loopee]

Interesting question but could you elaborate a little. I know what you mean by a 4-20mA signal with HART but what exactly are you trying to do with it?