The ARI STEVI-POS is a position controller for pneumatic control valves. Pneumatic control valves use spring action to close the valve if no air is supplied.
The ARI STEVI-POSsupplies air and reads the position of the valve piston, building a closed loop control positioning the control valve.
File:ARI SteviPos TypicalMounting.png
NOTE: The metal bar (A) in this picture is not the actuator, it provides the position feedback. Do not try to move the valve with this bar.
1 Hardware Connection[edit | edit source]
Electrically the only connection needed is the setpoint signal 4-20mA (translates to 0-100% position setpoint).
This signal also provides the neccessary power supply for the electronics.
The movement itself is done by air supply. Basically the Stevi-Pos acts as a proportional valve with feedback loop.
The 4-20mA setpoint signal is connected to terminals (+) and (-).
2 Commissioning[edit | edit source]
For each valve the initialization procedure must be done.
This takes about 70 seconds while the valve is moving and positioning and control parameters are automatically gathered.
Press the Reset button for longer than two seconds. The display will then show "Initialization".
The only thing to do after that is to set dip-switch Yin according to the direction.
This will directly change the movement direction.
Leave Operating mode to "Auto",
Tight closing to "Off" (all the way up (-) )
Deadband to "Auto"
With the arrow up/down keys you can see the actual current signal as well as entering the setup menu, check diagnostics and so on.
