US Patent 7764620 Diagnosis of redundant signal output channels connected in parallel

The invention relates to a device and a method for testing for wire breakage with a redundant signal output. To ensure the most fail-safe output in particular of a digital signal, whilst at the same time supplying a diagnosis function, it is proposed that two digital output modules should be connected in parallel, in particular with a diode integrated in each channel. The diagnosis function is enabled by a driver, which, in the event of a target value for the digital signal of logical “1”, connects the channel with a logical “1”, while setting a channel connected parallel thereto briefly to logical “0” and at the same time carrying out an interrupt test on the channel with logical “1”.