ABB TZIDC Digital Positioner V18345-1010551001 4-20mA

The TZIDC is an electronically configurable positioner with communication capabilities designed for mounting to pneumatic linear or rotary actuators. It features a small and compact design, modular construction, and excellent cost-performance ratio. Fully automatic determination of control parameters and adaptation to the final control element provide significant time savings and optimal control behavior.

An I/P module with subsequent pneumatic amplifier controls the pneumatic actuator. The proven I/P module proportionally converts the permanent electrical positioning signal from the CPU into a pneumatic signal used to adjust a 3/3-way valve. The air flow for pressurizing or depressurizing the actuator is continuously adjusted, achieving excellent control. When reaching the set point, the 3/3-way valve closes in center position to minimize air consumption. Four pneumatics versions are available: for single-acting or double-acting actuators, each with "fail-safe" or "fail-freeze" function.

If electrical power supply fails, the positioner output 1 is depressurized, and the pneumatic actuator's return spring moves the valve to the defined safe position. For double-acting actuators, the second output 2 is additionally pressurized.