VALSTEAM ADCA PI991 INTELLIGENT POSITIONER POSITIONERS & CONVERTORS
The microprocessor-controlled positioner PI991 is designed to control pneumatic valve actuators and can be operated locally or by means of control systems. The advanced diagnostic can be partially shown on the local LCD of the positioner or fully on a PC or a DCS workstation with a DTM based software (VALcare or Valve Monitor). The positioner is available with different communication protocols. This includes versions with analog setpoint (4 to 20 mA) and superimposed HARTor FoxCom signal; digital with FoxCom protocol, or fieldbus communication according to PROFIBUS-PA and FOUNDATION fieldbus H1 according to IEC 1158-2 based on FISCO. The PI991 also has the capability to control a Partial Stroke Test (PST) that offers operators a tool to identify the trouble-proof function of ESD (Emergency Shut Down) valves.