Safety switching apparatus and method for safe disconnection of a load
AssigneePilz GmbH & Co. KG
InventorRichard Veil
Life of this patent
Estimating the term…
Abstract
A safety switching apparatus for safe disconnection of a load in an automated installation has at least one input for receiving an analog input signal. It further has an A/D converter which converts the analog input signal to a digital signal. An evaluation and control unit controls at least one output switching element as a function of the digital signal. An analog signal combiner is designed to superimpose an analog test signal on the analog input signal in order to form an analog combination signal. The analog combination signal is supplied to the A/D converter. The operation of the safety switching apparatus can then be monitored for faults by means of the analog test signal.
Claims20
A safety switching apparatus for safe disconnection of a load in an automated installation, comprising
- at least one input for receiving an analog input signal,
- an analog signal combiner designed to superimpose an analog test signal on the analog input signal in order to form an analog combination signal,
- an A/D converter for converting the analog combination signal to a digital signal,
- an evaluation and control unit to which the digital signal is supplied, and
- at least one output switching element which is controlled by the evaluation and control unit as a function of the digital signal.
A method for safe disconnection of a load in an automated installation, comprising the steps of
- receiving at least one analog input signal,
- superimposing an analog test signal on the analog input signal in order to form an analog combination signal,
- converting the analog combination signal to a digital signal by means of an A/D converter,
- evaluating the digital signal, and
- controlling an output switching element as a function of the digital signal for safely disconnecting the load.
Dependencies are inferred from the claim text.