Linear actuator with Arduino Mega2560 assembling problem

Hi all,

Recently, I had a linear actuator option-I(Integrated controller with industrial and RC servo interface) and I want to connect it to Arduino Mega2560.

Details of actuator is as below:
1 - Green – Current input signal (4–20 mA interface mode)
2 - Blue – Voltage input signal (0–5V interface mode)
3 - Purple – Position Feedback signal (Proportional 0–3.3 V)
4 - White – RC input signal (RC-servo compatible mode)
5 - Red – Power (6V model or 12V model)
6 - Black – Ground

How do I wire it to Arduino?

I only know white wire is about servo's signal and red to 5V, black to GND.

What are green, blue, purple for?

If there's any advice, please let me know.

Many thanks!