LIMIT SIGNAL INDICATOR AND METHOD FOR OPERATING A LIMIT SIGNAL INDICATOR

• US 20100219961A1
• Filed: 03/02/2010
• Published: 09/02/2010
• Est. Priority Date: 03/02/2009
• Status: Active Grant

• Current Assignee: Samson AG
• Original Assignee: Samson AG
• Inventors: Vidal, Fausto Crespo, Klee, Dirk, Karte, Thomas, Schaertner, Karl-Bernd
• Granted Patent: US 8,576,086 B2
• Time in Patent Office: Days
• US Class Current: 340/635
• CPC Class Codes: F15B 15/2807 Position switches, i.e. means for sensing of discrete positions only, e.g. limit switches

Abstract

In a limit signal indicator for determining two positions of a pneumatically operated positioning device, a position sensor detects a position of the positioning device. A first signal transmission contact, a second signal transmission contact, and a microprocessor are provided. The first and the second signal transmission contacts each output a respective electrical limit position signal, the limit position signals representing an adoption of the first and the second positions or of at least one position of the positioning device above or below a predetermined set limit value. At least one of the signal transmission contacts is connected for signal transmission so that in case of a malfunctioning of a signal transmission, the switch amplifier is capable of generating an emergency signal above a maximum limit value or below a lower limit value, and to transmit the emergency signal to an external processing location. The microprocessor, upon detecting a specific operational malfunctioning, actuating the positioning device and executing an emergency procedure according to which the same emergency signal is generated and output at the second signal transmission contact.

Claims

1. A limit signal indicator for determining two positions of a pneumatically operated positioning device, comprising:

a position sensor for detecting a position of the positioning device;

a first signal transmission contact, a second signal transmission contact, and a microprocessor;

the first and the second signal transmission contacts each outputting a respective electrical limit position signal, said limit position signals representing an adoption of the first and the second positions or of at least one position of the positioning device above or below a predetermined set limit value;

at least one of the signal transmission contacts being connected to a switch amplifier for signal transmission so that in case of malfunctioning of a signal transmission, the switch amplifier being capable of generating an emergency signal above a maximum limit value or below a lower limit value, and to transmit the emergency signal to an external processing location;

said microprocessor, upon detecting a specific operational malfunctioning of at least one of the limit signal indicator, the positioning device, and a positioning drive, actuating the positioning device and executing an emergency procedure according to which the emergency signal is generated and output at the second signal transmission contact.

2. The limit signal indicator according to claim 1 wherein the microprocessor is electrically powered exclusively via the first, the second, or a third signal transmission contact, or via a further signal transmission contact.

3. The limit signal indicator according to claim 1 wherein the microprocessor is connected via an internal cable line with at least one of the first, the second, and a third signal transmission contact, or, if applicable, with a further signal transmission contact such that the emergency signal generated by the microprocessor is conducted to the respective signal transmission contact.

4. The limit signal indicator according to claim 1 wherein the microprocessor is driven by only one constant supply voltage present at one or several of the signal transmission contacts.

5. The limit signal indicator according to claim 1 wherein an operating element is provided that is actuated by an operation person in order to adjust positioning parameters for the limit signal indicator at the microprocessor.

6. The limit signal indicator according to claim 5 wherein a further microprocessor is provided disposed between the operating element and the microprocessor.

7. The limit signal indicator according to claim 1 wherein an enclosed housing is provided in which, beside the microprocessor, also an electro-pneumatic I/P-converter is received, wherein the housing has a pneumatic input for connection to a pneumatic source and an output for pneumatic coupling to the positioning drive, wherein the I/P-converter is connected to an output side at an inside of the housing.

8. The limit signal indicator according to claim 7 wherein a device for detecting a voltage signal generated by the microprocessor is provided for the I/P-converter, wherein the detected voltage signal indicates an operational state of the I/P-converter, and wherein the detected voltage signal is visualized on a display at an outside of the signal indicator.

9. The limit signal indicator according to claim 1 wherein the microprocessor, for differentiating a standardized emergency or alarm signal, is suitable to clock in a frequency specific manner in order to output at the respective signal transmission contact an electrical signal that is distinctively identifiable with respect to a detected operational malfunctioning.

10. The limit signal indicator according to claim 1 wherein if the emergency signal is generated, an end position signal at the second signal transmission contact is overwritten.

11. The limit signal indicator of claim 1 wherein the first and the second signal transmission contacts each comprise a Namur sensor.

12. A limit signal indicator for determining two positions of a pneumatically operated positioning device, comprising:

a position sensor for detecting a position of the positioning device;

a first signal transmission contact, a second signal transmission contact, and a microprocessor;

the first and the second signal transmission contacts each outputting a respective electrical limit position signal, said limit position signals representing an adoption of the first and the second positions or of at least one position of the positioning device different thereto and above or below a predetermined set limit value;

at least one of the signal transmission contacts being connected with a switch amplifier for transmitting signals, the switch amplifier being suitable in case of a malfunctioning of the signal transmission to generate an emergency signal above an upper limit value or below a lower limit value, and to transmit the emergency signal to an external processing location;

a third signal transmission contact;

said microprocessor, upon detecting an operational malfunctioning of at least one of the limit signal indicator, the positioning device, and the drive actuating the positioning device, executing an emergency procedure according to which an alarm signal is generated and output at the third signal transmission contact, said alarm signal representing the operational malfunctioning either

a) above or below a predetermined set limit value,

b) above the upper limit value, or

c) below the lower limit value.

13. The limit signal indicator according to claim 12 wherein the microprocessor is electrically powered exclusively via the first, the second, or the third signal limit transmission contact.

14. The limit signal indicator according to claim 12 wherein the microprocessor is connected via an internal cable line with at least one of the first, the second, and the third signal transmission contact, such that the emergency signal generated by the microprocessor is conducted to the respective signal transmission contact.

15. The limit signal indicator according to claim 12 wherein the microprocessor is driven by only one constant supply voltage at one or several signal of the signal transmission limit contacts.

16. The limit signal indicator according to claim 12 wherein an operating element is provided that is actuated by an operation person in order to adjust positioning parameters for the limit signal indicator at the microprocessor.

17. The limit signal indicator according to claim 16 wherein a further microprocessor is provided disposed between the operating element and the microprocessor.

18. The limit signal indicator according to claim 12 wherein an enclosed housing is provided in which, besides the microprocessor, also an electro-pneumatic I/P-converter is received, the housing having a pneumatic input connectable to a pneumatic source and an output for pneumatic coupling to the positioning drive, the I/P-converter being connected to an output side at an inside of the housing.

19. The limit signal indicator according to claim 18 wherein a device for detecting a voltage signal generated by the microprocessor for the I/P-converter is provided, the detected voltage signal indicating an operational state of the I/P-converter, and the voltage signal is visualized on a display at an outside of the signal indicator.

20. The limit signal indicator according to claim 12 wherein the microprocessor, for differentiating a standardized emergency or alarm signal, clocks it in a frequency specific manner in order to output at the respective signal transmission contact an electrical signal that is distinctively identifiable with respect to the detected operational malfunctioning.

21. The limit signal indicator according to claim 12 wherein, if the emergency signal is generated, an end position signal at the second signal transmission contact is overwritten.

22. The limit signal indicator according to claim 12 wherein the first, the second, and the third signal transmission contacts each comprise a Namur sensor.

23. A method for operating a limit signal indicator for determining two positions of a pneumatically operated positioning device, comprising the steps of:

generating a respective electrical position limit signals and outputting them at a respective first signal transmission contact and at a respective second signal transmission contact, when a position or at least one position of the positioning device differing therefrom is adopted, both position limit signals representing the positions above or below a predetermined set limit value;

connecting at least one of the signal transmission contacts with a switch amplifier for signal transmission which, in case of a malfunctioning of the signal transmission is suitable for generating and transmitting to an external processing location an emergency signal above an upper limit value or below a lower limit value; and

upon detection by the microprocessor of an operational malfunctioning of at least one of the limit signal indicator, the positioning device, and a drive actuating the positioning device, the microprocessor executing an emergency procedure according to which the emergency signal is generated and output at the second signal transmission contact.

24. A method for operating a limit signal indicator for determining two positions of a pneumatically operated positioning device, comprising the steps of:

outputting a respective electrical position limit signal at a respective first signal transmission contact and at a respective second signal transmission contact if a position or at least one position of the positioning device different therefrom is adopted, the two position limit signals representing positions above or below a predetermined set limit value;

connecting at least one of the signal transmission contacts to a switch amplifier for signal transmission, which in case of a malfunctioning of the signal transmission is suitable for generating an emergency signal above an upper limit value or below a lower limit value, and to transmit the emergency signal to an external processing station;

upon detection of an operational malfunctioning of at least one of the limit signal indicator, the positioning device, and one of the drives actuating the positioning device, the microprocessor executing an emergency procedure according to which an alarm signal is generated and output at a third signal transmission contact, said alarm signal representing the operational malfunction either

a) above or below a predetermined set limit value,

b) above the upper limit value, or

c) below the lower limit value.