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Industry consortium

FOUNDATION Fieldbus

An all-digital fieldbus that can execute control function blocks in field devices themselves, common in large continuous process installations.

N/A / Ethernet for HSEH1 (31.25 kbit/s) and HSE over EthernetEncryption: No

How it works

A link active scheduler coordinates deterministic publishing of function-block data between devices on an H1 segment.

Communication patternScheduled publisher/subscriber exchange on each segment.

Fact sheet

TransportH1 (31.25 kbit/s) and HSE over Ethernet
PortsN/A / Ethernet for HSE
AuthenticationNone
PurdueLevel 1 – Level 0
EnvironmentsContinuous process plants
DevicesTransmitter, Valve, Linking device, DCS controller
IndustriesOil & Gas, Chemical, Pharmaceutical

Why should I care?

Understanding FOUNDATION Fieldbus is what lets you tell a routine poll from a process-affecting command. Detection here depends on knowing which peers, function codes and timings are normal for your plant.

Key functions and operations

  • Function block execution
  • Scheduled data publishing
  • Device configuration

Security concerns

  • Control logic distributed into field devices widens the change-management surface
  • No authentication; physical and host-side controls dominate

What normal looks like

  • Stable segment live list and schedule

What deserves attention

  • Function block configuration changes outside change control

Hunting ideas

  • controller-logic-changes

Defensive controls

  • Treat configuration workstations as engineering assets
  • Capture device configuration baselines

Related ATT&CK for ICS techniques

T0836