– Incorrect mechanical attachment
– Incorrect transmission entered
– For NAMUR attachment: wrong pin position entered
– Valve is blocked
– Supply pressure too low. The supply pressure should be minimum 0.4 bar above the upper
spring range value (see chapter 3.1.2).
Air leakage of pneumatic system
The actuator stalls for a few seconds when the duty cycle is being determined initially. This
time is used by initialization to check the pneumatic system for leaks. If the control valve
moves more than 9.3 % from this resting position within 7 seconds, the relevant message is
issued and, additionally, an initialization warning is issued. Warning, initialization is not aborted.
Possible sources of error:
– Actuator not tight
– Signal pressure connection not tight.
Initialization status: Determining mechanical stops
When determining the mechanical stops, the initialization routine recognizes the spring ac-
tion and zero by completely venting and exhausting the actuator. In addition, the routine
checks whether the positioner can pass 100 % rated travel/nominal angle.
Initialization status: Determining minimum transit times
Transit time determination measures the time required by the valve to pass through the rated
travel/nominal angle from 0 % to 100 % and vice versa.
Initialization aborted through activation of forced venting option
If the implemented option forced venting is activated, the initialization procedure is aborted.
For implemented option forced venting it is required that between 6 V DC and 24 V DC be
applied to ter81 and –82.
Zero point error
The determined zero point does not lie within the acceptable tolerance limit of max.
±
5 % by
the internal absolute value for the detection of measured values. Initialization is aborted.
To eliminate this error, mechanical zero must be adjusted (see chapter 4.4.1).
The yellow pointer of the displacement sensor must then be approximately in alignment with
the marking on the cover plate.
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Messages and diagnosis
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