BS EN IEC 61158-5-4:2019 Industrial communication networks. Fieldbus specifications Application layer service definition. Type 4 elements

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

Link: BS EN IEC 61158-5-4:2019 Industrial communication networks. Fieldbus specifications Application layer service definition. Type 4 elements
Source: BSI Standards