When using 4-20 ma and 0-10v variable signals do the supplies for the variable signals need to originate from the measuring device?

I was hoping to find out if it's possible to continue to utilize a 4-20 ma output (from a pressure transducer - picked up by a proprietary industrial controller) and then also feed the same variable output (in parallel) from this transducer into another different industrial controller (motor vsd) as a 0-10v input, (provided the output voltage does vary from approximately 0-10v).

Any advice would be greatly appreciated.

 

Hai Neil
U r doing the right way of interfacing the pressure sensor with transducer which will generatre proportion output signal inthe form of voltage or current which will be feeded to your industrial controller to control the the final parameter.
It is advisable to use isolated analog output in the form of voltage/current before feeding it to the industrial controller.

 

Hello, Neil Charlton

It is not a must to use the power from the indicator / controller, external power supplies can be used. You can convert 4-20 mA into 2-10 V by a shunt resistance (500 ohms) but a special converter is required to convert 4-20 mA to 0 – 10 V. It is possible to connect a number of devices with one transmitter. The total resistance of these devices should be within the specified maximum value for the particular transmitter and these devices must have isolated inputs.

 

Hi

You can use Avago's linear opticoupler such as HCNR201 to do that.There are some ANs to tell you how.