BS EN IEC 61158-5-23:2019 Industrial communication networks. Fieldbus specifications Application layer service definition. Type 23 elements

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

Link: BS EN IEC 61158-5-23:2019 Industrial communication networks. Fieldbus specifications Application layer service definition. Type 23 elements
Source: BSI Standards