Field
Sensor / Transmitter
A device measuring a physical quantity and reporting it to the control system.
High criticalityLevel 0
What it does
Converts pressure, temperature, flow, level or position into a signal.
Typically locatedOn the process itself.
At a glance
PurdueLevel 0
CategoryField
Protocolshart, foundation-fieldbus, profibus
Talks toController, Asset management system
Common vendorsEmerson, Endress+Hauser, Yokogawa, Honeywell
Why should I care?
Sensor / Transmitter sits at Level 0. Compromise here is not just a data problem — it changes what the physical process does or what operators can see and control.
Common security problems
- Configuration changes require only physical or asset-management access
- Calibration drift indistinguishable from tampering without records
If it is compromised
- Falsified process view leading to incorrect control action
What to monitor
- Configuration and range changes
- Diagnostic status
- Value plausibility vs related measurements
How to defend it
- Protect asset management systems
- Reconcile configuration changes with work orders
- Cross-check redundant measurements
Related