The digital Modular Valve Positioner is controlled by equipment that has transistor-transistor logic, also known as TTL, or switch closure outputs
The serial Modular Valve Positioner is designed for applications that can utilize RS-232 serial communication. The serial protocol provides better error handling and diagnostics that are especially helpful in critical applications. With serial command, up to 16 serial Modular Valve Positioners can be connected via a daisy chain. This model can be programmed using simple ASCII commands.
Both the digital and serial Modular Valve Positioners offer an optional cover. Units with a cover are typically used when the positioner is sitting on a bench top or needs to be better protected from fumes or harsh chemicals while the non-covered version is meant for internal integration into higher-level equipment.