signal 4-20 mA generator with time

[andreeeea]

Hi,

is possible to program a mA ramp output as a function of the time? automatically not manually.

I mean, I would like to change automatically the amperage with the time.

0 min - 4 mA
2 min - 4.56 mA
4 min - ...

What can I use?

 

[GroovyGuy]

Andrea,
Need more info.
What are you trying to accomplish here? (ie where does this 4-20mA 'time' signal need to go ? Is the 'time' going to be displayed on a local panel?)
What type / model number of PLC do you have?
How is the existing Operator Interface currently handled?
GG

"I have not failed. I've just found 10,000 ways that won't work." Thomas Alva Edison (1847-1931)

 

[IRstuff]

Certainly, one could imagine a 4-20mA voltage sensor tied to an Arduino programmed to output specified voltages at specified times. It's not elegant, but it should work.

There are programmable calibrators that could probably be suborned into supporting your application

You could build your own with commercial components:

http://www.ti.com/lit/ds/symlink/dac161s997.pdf

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[aap2]

You should be able to use an Arduino since it has time delay and analog outputs.

 

[UniCO2]

I have programmed my AO channels to do this with the DCS or PLC and then wired them into my AI channels.