Samson 3767 - Page 8

8 EB8355-2EN
Designandprincipleofoperation
When a control signal corresponding to the
binarysignal'1'(ON)isappliedtothein-
put, the signal pressure p
st
is applied to the
actuator, allowing the valve to move accord-
ingtotheinputsignalissuedbythecontrol
equipment.
Positionerwithpositiontransmitter
A positioner containing a position transmit-
tercannotbeequippedwithintegratedlimit
contacts or an integrated solenoid valve
since the position transmitter requires most of
the space inside.
The position transmitter is used to assign the
valve position, i.e. the valve travel, to an out-
putsignalof4to20mA.Thetuningofthe
positiontransmitterensuresthatbothend
positions "valve CLOSED" or "valve OPEN"
aswellasallintermediatepositionscanbe
signalized. Since the valve position is signal-
ized independently of the input signal to the
positioner, the position transmitter is a suit-
ableoptionforcheckingtheactualvalvepo-
sition.