I'm working on an embedded project that takes has an input that ranges from 4-20ma. This is normally provided by an external controller, but I'm working on a test bed. Controlling voltage is easy - just stick a potentiometer in between the power supply and the input.

AMP & VOLT DUAL SIGNAL GENERATOR: Multifunctional DROK signal generator kit is able to generate ampere & voltage by one module, which generate 0/4 - 20mA current signal and 0-10V voltage signal just by rotating a multi-cycle precise potentiometer, simple and handy. The ME series of Gefran, are pressure transmitters for using in High temperature environment and specifically designed for melt pressure measurement and available only to be used in large-scale fixed installations or in large-scale stationary