SC 6 - Telecommunications and information exchange between systems

ISO/IEC 14908-1:2012 specifies a communication protocol for local area control networks. The protocol provides peer-to-peer communication for networked control and is suitable for implementing both peer-to-peer and master-slave control strategies. ISO/IEC 14908-1:2012 describes services in layers 2 to 7. In the layer 2 (data link layer) specification, it also describes the Medium Access Control (MAC) sublayer interface to the physical layer. The physical layer provides a choice of transmission media. The interface described in ISO/IEC 14908-1:2012 supports multiple transmission media at the physical layer. In the layer 7 specification, it includes a description of the types of messages used by applications to exchange application and network management data.

ISO/IEC 14908-3:2011 specifies the control network Power Line (PL) channel and serves as a companion document to ISO/IEC 14908-1. It presents the information necessary for the development of a PL physical network and nodes to communicate and share information over that network.  
ISO/IEC 14908-3:2011 covers the complete physical layer (OSI layer 1) including the interface to the Medium Access Control (MAC) sublayer and the interface to the medium. It includes parameters specific to the PL channel type, even though the parameters may be controlled at an OSI layer other than layer 1. ISO/IEC 14908-3:2011 also provides a set of guideline physical and electrical specifications for the power line environment as an aid in developing products for that environment.

ISO/IEC 14908-2:2011 specifies the control network protocol (CNP) free-topology twisted-pair channel for networked control systems in local area control networks and is used in conjunction with ISO/IEC 14908-1. The channel supports communication at 78,125 kbit/s between multiple nodes, each of which consists of a transceiver, a protocol processor, an application processor, a power supply and application electronics.  
ISO/IEC 14908-2:2011 covers the complete physical layer (OSI Layer 1), including the interface to the Media Access Control (MAC) sublayer and the interface to the medium. Parameters that are controlled by other layers but control the operation of the physical layer are also specified.

ISO/IEC 14908-4:2011 specifies the transporting of the Control Network Protocol (CNP) packets for commercial local area control networks over Internet Protocol (IP) networks using a tunnelling mechanism wherein the CNP packets are encapsulated within IP packets. It applies to both CNP nodes and CNP routers.
The purpose of ISO/IEC 14908-4:2011 is to ensure interoperability between various CNP devices that wish to use IP networks to communicate using the CNP.