Safety Control for the Secure Operation of a Technical Plant and Method of Operating a Safety Control

• US 20150309481A1
• Filed: 04/06/2015
• Published: 10/29/2015
• Est. Priority Date: 04/25/2014
• Status: Active Grant

• Current Assignee: Sick AG (Sick)
• Original Assignee: Sick AG (Sick)
• Inventors: SAUMER, Markus
• Granted Patent: US 10,114,345 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05B 9/02 electric

Abstract

In order to reduce the power-loss in digital inputs of a safety control, a safety control for the secure operation of a technical plant is provided that comprises at least one input unit for the reception of a signal of at least one signal generator connected to the technical plant, a control unit for the reading in of the received signal and for generating a control command, and at least one output unit for the transmission of the generated control command to at least one connected actuator of the technical plant, wherein the input unit has a switching element at the input side that can be controlled by means of the control unit and is configured in such a way that the switching element can be actuated by means of the control unit directly prior to the reading in of the received signal, in particular can be closed, and can be actuated again by means of the control unit, in particular opened, following the reading in of the received signal.

Claims

1. A safety control for the secure operation of a technical plant, comprising at least one input unit for receiving a signal of at least one connected signal generator of the technical plant, a control unit for reading in the received signal and for generating a control command, and at least one output unit for transmitting the generated control command to at least one connected actuator of the technical plant, wherein the input unit has a switching element at the input side that can be controlled by means of the control unit and is configured in such a way that the switching element can be actuated by means of the control unit directly prior to the reading in of the received signal and can be actuated again by the control unit after the reading in of the received signal.

2. The safety control in accordance with claim 1, wherein the switching element can be closed by the control unit directly prior to the reading in of the received signal and can be opened by the control unit after the reading in of the received signal.

3. The safety control in accordance with claim 1, wherein the switching element can be periodically controlled by means of the control unit.

4. The safety control in accordance with claim 1, wherein the switching element can be controlled at intervals discrete in time by means of the control unit.

5. The safety control in accordance with claim 1, wherein the switching element is one of an electronic switch and an electromechanical switch.

6. The safety control in accordance with claim 1, wherein the signal generator is an optoelectronic sensor, an emergency cutoff switch or the like.

7. The safety control in accordance with claim 1, wherein the control unit is configured to determine a state of the input unit from an actuation of the switching element.

8. The safety control in accordance with claim 7, wherein the actuation of the switching element is composed of closing and opening.

9. A method of operating a safety control having at least one input unit for the reception of a signal of at least one connected signal generator of a technical plant, a control unit for reading in the received signal and for generating a control command and at least one output unit for the transmission of the generated control command to at least one connected actuator of the technical plant, wherein the signal of the signal generator is transmitted to the input unit and the control unit actuates a switching element arranged at the input side of the input unit in such a way that the signal is read in and the switching element is actuated again thereafter, such that the input unit is separated from the signal generator.

10. The method in accordance with claim 9, wherein the control unit closes a switching element arranged at the input side of the input unit such that the signal is read in and opens the switching element again thereafter such that the input unit is separated from the signal generator.

11. The method in accordance with claim 9, wherein the control unit periodically actuates the switching element.

12. The method in accordance with claim 9, wherein the control unit closes and opens the switching element at intervals discrete in time.

13. The method in accordance with claim 9, wherein the control unit compares a state of the switching element on closing and opening and therefrom determines a secure error-free operating readiness of the switching element and of the input unit.

14. The method in accordance with claim 13, wherein, following the switching on or switching off of the switching element respectively, the control unit determines an error of the switching element or of the input unit respectively, when a signal level, a status pin or the like of the switching element and/or of the input unit remains unchanged.