Method for operating a redundant system for supplying a load with a voltage, whereby - a first output voltage is connected via a first output of a first output module and - a second output voltage is connected via a second output of a second output module to a load for controlling said load, with the following steps: (i) in the first output module a test of a first electrical current path is carried out by a measurement means belonging to this output module from the first output via the load and in the second output module a test of a second electrical current path from the second output via the load is carried out by a measurement means belonging to this output module, characterised in that (ii) if the result of the test is that a measured value of the current of the respective electrical current path (5a, 5b) lies below a threshold value, the output voltage (U1, U2) of the output module (1, 2) at which the undershooting of the threshold value was established by the test result is switched off, (iii) and by means of a readback input (26a, 26b) which is connected to the first or second output (A1, A2) a binary test is carried out in the output module (1, 2) in which the output voltage (U1, U2) was switched off which delivers a logical one if a voltage is still present at its output (A1, A2) and delivers a logical zero if there is no voltage present at its output (A1, A2), (iv) for the test result zero an error message is generated and for the test result one the binary test is continued in cycles for a predeterminable duration of a wait time, whereby within the duration of the wait time the output module (1, 2) with the output voltage (U1, U2) still switched on is operated such that its output voltage (U1, U2) is switched off, whereby this switching-off is registered by the output module (1, 2) which is carrying out the binary test and subsequently this switches on its output voltage (U1, U2) again and thereby takes over the supply of the load via the electrical current path (5a, 5b) connected to its output (A1, A2), whereby a test is carried out by the measurement means associated with this output module as to whether a current is flowing and, in the event of no current flowing, an error message is generated. - a first output voltage is connected via a first output of a first output module and - a second output voltage is connected via a second output of a second output module to a load for controlling said load, with the following steps: (i) in the first output module a test of a first electrical current path is carried out by a measurement means belonging to this output module from the first output via the load and in the second output module a test of a second electrical current path from the second output via the load is carried out by a measurement means belonging to this output module, characterised in that (ii) if the result of the test is that a measured value of the current of the respective electrical current path (5a, 5b) lies below a threshold value, the output voltage (U1, U2) of the output module (1, 2) at which the undershooting of the threshold value was established by the test result is switched off, (iii) and by means of a readback input (26a, 26b) which is connected to the first or second output (A1, A2) a binary test is carried out in the output module (1, 2) in which the output voltage (U1, U2) was switched off which delivers a logical one if a voltage is still present at its output (A1, A2) and delivers a logical zero if there is no voltage present at its output (A1, A2), (iv) for the test result zero an error message is generated and for the test result one the binary test is continued in cycles for a predeterminable duration of a wait time, whereby within the duration of the wait time the output module (1, 2) with the output voltage (U1, U2) still switched on is operated such that its output voltage (U1, U2) is switched off, (i) in the first output module a test of a first electrical current path is carried out by a measurement means belonging to this output module from the first output via the load and in the second output module a test of a second electrical current path from the second output via the load is carried out by a measurement means belonging to this output module, (ii) if the result of the test is that a measured value of the current of the respective electrical current path (5a, 5b) lies below a threshold value, the output voltage (U1, U2) of the output module (1, 2) at which the undershooting of the threshold value was established by the test result is switched off, (iii) and by means of a readback input (26a, 26b) which is connected to the first or second output (A1, A2) a binary test is carried out in the output module (1, 2) in which the output voltage (U1, U2) was switched off which delivers a logical one if a voltage is still present at its output (A1, A2) and delivers a logical zero if there is no voltage present at its output (A1, A2), (iv) for the test result zero an error message is generated and for the test result one the binary test is continued in cycles for a predeterminable duration of a wait time, whereby within the duration of the wait time the output module (1, 2) with the output voltage (U1, U2) still switched on is operated such that its output voltage (U1, U2) is switched off,