Analog signal...mA vs. DC?
Analog signal...mA vs. DC?
(OP)
I'm designing a new controller that has several analog inputs...pressure and motor current. I have a choice of 4-20mA or 0-5VDC transducers. Is one type more desirable or beneficial over the other?





RE: Analog signal...mA vs. DC?
----------------------------------
Sometimes I only open my mouth to swap feet...
RE: Analog signal...mA vs. DC?
0-5V:
Less hassles providing the excitation.
No offset hassles.
More available sensors.
Sensors often less expensive.
4-20mA:
Only two wires (usually)
Less noise sensitive. (As Scotty sez)
Input scaling easier.
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Analog signal...mA vs. DC?
RE: Analog signal...mA vs. DC?
RE: Analog signal...mA vs. DC?
Plesae read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>
RE: Analog signal...mA vs. DC?
What does your controller do? What is it supposed to communicate with? Motor current very often is a V signal. Pressure very often is mA signal. Find out what you are supposed to communicate with and select your inputs accordingly. Many systems have a basic 0-5 V input and a switchable resistor to accept mA signals. Software is then used to change the 0-20 mA into a 4-20 mA signal.
Outputs need a little more design work if you want to have both signal types. There you should find out what the partners are and how they communicate.
Either you know what the signals are and design for that - or you do not know and design to be flexible. It is your choice. Not ours.
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Analog signal...mA vs. DC?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Analog signal...mA vs. DC?
John
RE: Analog signal...mA vs. DC?
can take more filtering or even highfrequency pre-
emphasys.
If there is question about the noise, it would be simpler
to use digital interface.
Plesae read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>