Re: [foxboro] FBM 01 Connection issues
- From: "Joseph M. Riccardi" <Joe@xxxxxxxxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Mon, 27 Sep 2010 15:06:30 -0400
Gonzalo,
If it is a 4 wire transmitter, as most Gas analyzers are, you do not use the
P terminal. Simply connect the + to + and - to - terminals.
Joseph M. Riccardi
DCS Services - Industrial Process Control
Joe@xxxxxxxxxxxxx
"To give real service you must add something that cannot be bought or
measured with money; and that is sincerity and integrity." - Donald A. Adams
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx] On
Behalf Of Gonzalo Díaz
Sent: Monday, September 27, 2010 9:12 AM
To: foxboro@xxxxxxxxxxxxx
Subject: [foxboro] FBM 01 Connection issues
Hello to you all, I have a problem trying to connect a 4-20 mA gas detector
to a FBM01 card.
Te gas detector has the following connection diagram (hope my drawings wont
be affected by mail systems):
o------- +24vcc
o------- Signal
o------- DC Common
As you may see, the sensor needs to be powered, and the "signal" comes as a
current source from the device, in a separate cable
In the other hand, the connection diagram for the FBM01 is as following:
o------- P
o------- (+)
o------- (-)
I thought that the following connection would work, so I connected the
device as following:
DEVICE SIDE / FBM01 SIDE
+24VCC -------o------- P
Signal -------o------- (+)
DC Com -------o------- (-)
But it didn't work. The way it DID work, was as following:
+24VCC -------o------- to external power source (+24)
Signal -------o------- FBM01 (+)
DC Com -------o------- FBM01 (-) also attached to external power source (-)
Hope you can understand it. I connected the DC Common signal of the device
to the FBM01 (-) and ALSO to the external power source (-) terminal.
I do know this should work (the current loop goes through the external power
source instead of the FBM01 module) but I also know that it is not correct
to "bind" two different "negatives" from different sources.
Any ideas? Why the first option didn't work? How did you managed to do this
on your systems??
Best regards!
Gonzalo Diaz
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
_______________________________________________________________________
This mailing list is neither sponsored nor endorsed by Invensys Process
Systems (formerly The Foxboro Company). Use the info you obtain here at
your own risks. Read http://www.thecassandraproject.org/disclaimer.html
foxboro mailing list: //www.freelists.org/list/foxboro
to subscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=join
to unsubscribe: mailto:foxboro-request@xxxxxxxxxxxxx?subject=leave
Other related posts:
