Fisher 3590 Valve Positioner Manual Link

Standard 4–20 mA DC, 10–50 mA, or split-range options. Internal Resistance: Approximately 300 ohms.

Proper installation is critical to prevent "hunting" or sluggish response. According to the Fisher 3590 manual, these steps are foundational: fisher 3590 valve positioner manual

Supports travel ranging from 7/16 to 4 1/8 inches. Standard 4–20 mA DC, 10–50 mA, or split-range options