Communication interface module for a modular control device of an industrial automation system, having - a connection for a backplane bus system of the modular control device, the communication interface module being able to be connected to a central unit of the modular control device via the backplane bus system, - at least one first and one second transmitting and receiving unit each having an interface for a network connection of a redundant subnetwork, - a coupling element which is connected to the first and second transmitting and receiving units and can be used to connect the connection for the backplane bus system to the first and second transmitting and receiving units, - a signal processing unit which is connected to the coupling element and has a multiplexer unit for forwarding messages to be transmitted to both transmitting units in a parallel manner and a redundancy handling unit for processing messages received by both receiving units, the redundancy handling unit comprising a filter unit which is set up to detect received redundant messages, characterized in that - both transmitting and receiving units have an identical network address and an identical device identifier, - the signal processing unit is configured for bursty message transmission according to a media redundancy protocol and for smooth message transmission according to a parallel or ring redundancy protocol inside an industrial communication network and can be selectively changed over to a bursty or smooth transmission mode, and the signal processing unit is deactivated in the bursty transmission mode, - the signal processing unit is configured and set up to allocate a sequence number to a message to be smoothly transmitted only in the smooth transmission mode, and the redundancy handling unit is configured and set up for duplicate filtering of a message transmitted smoothly only in the smooth transmission mode. - a connection for a backplane bus system of the modular control device, the communication interface module being able to be connected to a central unit of the modular control device via the backplane bus system, - at least one first and one second transmitting and receiving unit each having an interface for a network connection of a redundant subnetwork, - a coupling element which is connected to the first and second transmitting and receiving units and can be used to connect the connection for the backplane bus system to the first and second transmitting and receiving units, - a signal processing unit which is connected to the coupling element and has a multiplexer unit for forwarding messages to be transmitted to both transmitting units in a parallel manner and a redundancy handling unit for processing messages received by both receiving units, the redundancy handling unit comprising a filter unit which is set up to detect received redundant messages, - both transmitting and receiving units have an identical network address and an identical device identifier, - the signal processing unit is configured for bursty message transmission according to a media redundancy protocol and for smooth message transmission according to a parallel or ring redundancy protocol inside an industrial communication network and can be selectively changed over to a bursty or smooth transmission mode, and the signal processing unit is deactivated in the bursty transmission mode, - the signal processing unit is configured and set up to allocate a sequence number to a message to be smoothly transmitted only in the smooth transmission mode, and the redundancy handling unit is configured and set up for duplicate filtering of a message transmitted smoothly only in the smooth transmission mode.