BS EN IEC 61158-3-4:2019 Industrial communication networks. Fieldbus specifications Data-link layer service definition. Type 4 elements

Communication networks
Interfaces (data processing)
Communication procedures
Computer networks
Industrial
Data link layer (OSI)
Automatic control systems
Bus networks
Fieldbus
Open systems interconnection
Process control
Data transmission

Link: BS EN IEC 61158-3-4:2019 Industrial communication networks. Fieldbus specifications Data-link layer service definition. Type 4 elements
Source: BSI Standards