+/- 10V to 4-20mA converter

tauro0221:
Hi,
"signal source which is capable of only -10V to + 10V" Is this is a home made or it is a commercial product? Can you right down the model and who make it?

This is a output from a Analog data acquisition card from National Instruments. Model PC1-6229. Outputs +/- 10V with 16 bit resolution.