Abstract: To enable an increase in a service life of a modular safety relay circuit, a modular safety relay circuit is provided for the safe switching on and/or off of at least one machine comprising at least one relay module to which the at least one machine is connected, wherein the relay module comprises at least two relay contacts that are connected in series and that can be brought from a first position into a second position and vice versa; and wherein one relay contact switches in advance by a delay of the other relay contact; and a control unit controlling the relay contacts that alternatingly controls the relay contacts in accordance with a state detection of the relay contacts with the delay.

Abstract: To enable a safe monitoring with a small cabling effort of a modular safety relay circuit, a modular safety relay circuit for the safe control of at least one machine is provided comprising a safety relay unit that has at least one forcibly guided relay for the safe switching on and off of the machine and that generates output signals in dependence on input signals, wherein the input signals are provided by at least one connected signal transmitter and the output signals are communicated to the at least one machine; and at least one expansion relay unit for providing additional output connectors so that additional machines can be connected; wherein the expansion relay unit has at least one respective forcibly guided relay for the safe switching on and off of the machine and is monitored by means of a monitoring signal.

Abstract: To enable an increase in a service life of a modular safety relay circuit, a modular safety relay circuit is provided for the safe switching on and/or off of at least one machine comprising at least one relay module to which the at least one machine is connected, wherein the relay module comprises at least two relay contacts that are connected in series and that can be brought from a first position into a second position and vice versa; and wherein one relay contact switches in advance by a delay of the other relay contact; and a control unit controlling the relay contacts that alternatingly controls the relay contacts in accordance with a state detection of the relay contacts with the delay.

Abstract: To enable a safe monitoring with a small cabling effort of a modular safety relay circuit, a modular safety relay circuit for the safe control of at least one machine is provided comprising a safety relay unit that has at least one forcibly guided relay for the safe switching on and off of the machine and that generates output signals in dependence on input signals, wherein the input signals are provided by at least one connected signal transmitter and the output signals are communicated to the at least one machine; and at least one expansion relay unit for providing additional output connectors so that additional machines can be connected; wherein the expansion relay unit has at least one respective forcibly guided relay for the safe switching on and off of the machine and is monitored by means of a monitoring relay.