I reverse engineered this board. It is an isolation amplifier setup. The resistors have been chosen for a gain of 1X. There are three different types of output: 0-10V, 0-5V, and 4-20mA. I powered the board with a +/- 12V power supply. The output does follow the input polarity, so if you put in -5V the output will also be -5V. You can change the gain by selecting different R1 & R2 values. I recommend checking the online specs for additional details and limitations of the AD204KY device. If you need a power supply for this, let me know and I will post one for sale.