Valve positioner and user interface for valve positioner

1. A smart valve positioner comprising a housing and a housing cover, the housing encompassing control circuitry connectable to a field control line, and a local user interface with one or more buttons and optionally a display inside the housing under the housing cover for locally operating the valve positioner, wherein the local user interface comprises one or more non-mechanical touch buttons enclosed inside the housing, and the housing cover is configured to make the touch buttons user-operable from outside the housing by touching the housing cover,

wherein each of the touch buttons are arranged to detect an electrical or optical influence of a user finger in the close proximity, and the housing cover is adapted to enable such electrical or optical influence through the housing cover to the touch button when the user finger touches a predetermined point on the housing cover, and

wherein a thickness of the housing cover is reduced at said predetermined point in comparison with an overall thickness of the housing cover.

2. A smart valve positioner comprising a housing and a housing cover, the housing encompassing control circuitry connectable to a field control line, and a local user interface with one or more capacitive touch buttons and a display enclosed inside the housing under the housing cover for locally operating the valve positioner, wherein the housing cover can be opened and the same capacitive touch buttons can be operated both with the housing cover closed and open, each of the capacitive touch buttons being arranged to detect an electrical influence of a user finger in the close proximity, and the housing cover is configured to enable such electrical influence through the housing cover to the capacitive touch button when the user finger touches a predetermined point on the housing cover and thereby make the capacitive touch buttons user-operable from outside the housing by touching the housing cover, when the housing cover is closed, and wherein the capacitive touch buttons are user-operable by directly touching the capacitive touch buttons inside the housing, when the housing cover is open.

3. A smart valve positioner as claimed in claim 2 , wherein a thickness of the housing cover is reduced at said predetermined point in comparison with an overall thickness of the housing cover.

4. A smart valve positioner as claimed in claim 2 , wherein there is an air gap or a shock-absorbing intermediate layer between the housing cover and the local user interface.

5. A smart valve positioner as claimed in claim 2 , wherein the capacitive touch buttons comprise capacitive touch buttons with a non-conductive overlay, and wherein the housing cover is made of non-conductive material, and wherein an elastic conductive element is locally arranged between the non-conducting housing cover and the non-conducting overlay at locations of said capacitive touch buttons.

6. A smart valve positioner as claimed in claim 2 , wherein the user interface is configured to assume a first user access mode level as a default to thereby allow use of the capacitive touch buttons through the housing cover for a first set of user operations, and wherein the user interface is configured to require a dedicated access code for entering a further user access mode level to thereby allow use of the capacitive touch buttons through the housing cover for one or more further sets of user operations.

7. A smart valve positioner as claimed in claim 6 , wherein said first set of user operations include reading operations, and said one or more further sets of user operations include reading operations and procedures for locally controlling parameters and operation of the smart valve positioner.

8. A smart valve positioner as claimed in claim 6 , wherein the user interface is configured to assume the further user access mode level automatically for a predetermined period of time upon connecting a power to the valve positioner, and wherein the first user access mode level is resumed after expiry of the predetermined period of time from the connection of the power.

9. A smart valve positioner as claimed in claim 2 , wherein the local user interface panel with the housing cover closed is configured to assume a first user access mode level as a default to thereby allow use of the capacitive touch buttons through the housing cover for a first set of user operations, and wherein the local user interface is responsive to an opening of the housing of the valve positioner to assume a further user access mode level to thereby allow use of the capacitive touch buttons through the closed housing cover for one or more further sets of user operations.

10. A smart valve positioner as claimed in claim 2 , wherein the local user interface with the housing cover closed is configured to assume a first user access mode level as a default to thereby allow use of the capacitive touch buttons through the housing cover a first set of user operations, and wherein the local user interface with the housing cover opened is configured to assume a further access user access mode level to thereby allow use of the capacitive touch buttons directly on the local user interface for one or more further sets of user operations.

11. A smart valve positioner as claimed in claim 2 , wherein the local user interface is provided with electrical, optical or mechanical detector detecting whether the housing or the housing cover is opened or closed.

12. A smart valve positioner as claimed in claim 11 , wherein the housing cover comprises at least one magnetic element, and wherein the local user interface panel is provided with a magnetic sensor or a Hall sensor configured to detect the presence of the magnetic element.

13. A valve assembly comprising

a valve;

an actuator; and

a smart valve positioner; the smart valve positioner further comprising a housing and a housing cover, the housing encompassing control circuitry connectable to a field control line, and a local user interface with one or more buttons and a display inside the housing under the housing cover for locally operating the valve positioner, wherein the local user interface comprises one or more touch buttons enclosed inside the housing, and the housing cover is configured to make the touch buttons user-operable from outside the housing by touching the housing cover, and wherein the local user interface is provided with electrical, optical or mechanical detector detecting whether the housing or the housing cover is opened or closed.