ABB Instrumentation”s TZIDC electro-pneumatic positioner mounts to pneumatic linear or rotary actuators. The positioner is designed for 4-20 mA control systems and offers a compact design, modular construction, and an advantageous cost-performance ratio. The positioner automatically adapts its control settings to final control elements, such as valves, offering optimal control behavior. Modularity permits future enhancements by various optional retrofits and plug-ins. An I/P module within the TZIDC positioner adjusts a 3/3-way valve that regulates airflow for pressurizing or depressurizing the actuator to maintain position. When the actuator reaches the position set point, the 3/3-way valve closes in its center position to minimize air consumption. The positioner comes in four different pneumatic versions: single-acting or double-acting actuators, each with a “failsafe” or “fail-freeze” function. The positioner has a built-in operating panel providing a two-line LCD and four pushbuttons for optimal local configuration, simple commissioning, and operational monitoring. Alternatively, communication capabilities permit remote configuration. TZIDC models are available with direct serial communications, as well as HART, PROFIBUS PA, and FOUNDATION fieldbus protocols. Additional digital input and output functions expand the positioner’s capabilities. The digital input can activate various protective functions in the device via the process control system. A digital output allows the sending of collective alarms or fault messages.