Patent ID: 7868619
Filing Date: 2011-01-11
Classification: G05B

Abstract:
1. A method for monitoring connections of a switch intended for activating a safety function of a device, the switch having at least two poles, the method comprising: supplying, from a voltage supply, voltages to first sides of two poles of the switch through first connections; supplying, when the switch is in a conductive state, the voltages supplied to the first sides of said two poles of the switch from second sides of said two poles of the switch further to the device through second connections; monitoring the voltages supplied to the device through the first connections, the switch and the second connections; forming a voltage difference between the voltages to be supplied to the first sides of said two poles of the switch; and detecting a connection failure in response to the difference between the voltages supplied to the device through the first connections, the switch and the second connections not corresponding with said formed voltage difference or to the difference between the voltages supplied to the device through the first connections, the switch and the second connections being substantially zero.