0-10V Output 2

[Ridly]

Job has 5 existing 0-10V outputs for process, I need to add
a recorder for the process. The distance is approx. 150-200
feet. Is it possible to add a signal duplicator, and then
convert one of the outputs to 4-20ma for the recorder!

 

[danw2]

Yes, lots of vendors make I/O modules that convert from 0-10V to 4-20mA. The modules usually need a power supply.

You're sure the recorder doesn't take a 0-10V input? If it does, then pulling a twisted pair of wires to test a 200' run with the 0-10V signal would be feasible. Why not try the voltage signal before you go to 4-20?

 

[Skogsgurra]

You may need to be careful with those 10 V signals. If they are used for other purposes than your recorder, they may pick up noise if you connect a 200' cable. Easiest way is to use a small resistor-capacitor-resistor filter (an R-C-R "T" filter) to keep noise away from the analogue output. Most recorders with a 10 V input have 1 Mohm impedance, so it is not a problem making the R 1 kohm. Making C 1 microfarad will suppress noise and still leave you with a few hundred Hz band-width.

Gunnar Englund

http://www.gke.org

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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[Ridly]

Thanks danw2, Yes, The recorder is multi-configurable

 

[dpc]

FWIW, our practice is to use 0-10V within control panels, but we always convert to 4-20mA when running between panels to reduce noise problems - as Skogsgurra has already indicated can be a problem with voltage signals.

 

[Ridly]

Can I run a couple of hundred feet with loss of signal!

 

[itsmoked]

With 4-20mA yes, certainly.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[danw2]

There's no good way to predict what the 0-10V signal will look like when it reaches the recorder, unless you actually connect it and see.

I've done it where it's worked OK, and where it hasn't. The problem where it didn't work was noise.

Since you need a twisted pair wire run, why not pull the wire, connect it up and see what the recorded signal looks like? If it's clean, you're up and running. If it's too noisy, then you'll have to get an I/O module and convert to 4-20.

Dan

 

[itsmoked]

I concur with danw2 but would caution you to design for the 4-20mA situation so you don't find you need to pull excitation power for the 4-20mA converter and haven't.

You have a good chance of the 0-10V working as that is a large signal. Think of thermocouple signals that often run hundreds of feet thru industry and work well enough with microvolt signals.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[dpc]

As for distances, you can run 4-20 mA many thousands of feet.