Converting 4-20 mA Signal to RS 232


Thread Starter

Parag Bhadra

Can somebody help me with the details of a simple 4-20 mA to RS232 converter (Single Channel or multiple channel).

I need to study signals from Instruments which are already connected to Electronic Controllers and PLCs.

Is there anything similar where RS232 signals (O/P from PCs) can be converted to 4-20 mA signals.

Gabriele Corrieri

You must check that your interface is passive or active ...
If you have discovered this particular, e-mail to me with pinout of current loop port, then I'll try to make a converter.


Gabriele Corrieri
[email protected]

Sanjay Patel

Dear Friend

Our company prepard the low cost card which as under
(1) 24 digital input 24 digital output
(2) 48 digital intput 24 digital output
(3) 8 analog input and 8 analgo output

using this card u can retrieve the data on PC as well as control the I/O. We have prepared the library to write the logic accoring to your
requirement or we will develop the same as per your requirement. Data will be availabel in modbus protocol. You can access the data using
any modbus software or we also develop the same for you. For more detail please contact me on emailor mobile.


Sanjay Patel
System Analyst
Tectona SoftSolutions (P) Ltd.
You will have to use opto couplers of some sort. to keep all signals at correct levels.
then you are free after that what to use.