scope:

This series of standards applies to telecontrol equipment and systems with coded bit serial data transmission for monitoring and controlling geographically widespread processes. This standard covers asynchronous data transmission with half duplex and duplex link protocols operating with window size one for message transfers. This section specifies the basic requirements for services to be provided by the link plus physical layers, for telecontrol applications. In particular it specifies standards on coding, formating and specified data integrity requirements.