Publishing data across a data diode for secured process control communications

To secure communications from a process plant across a unidirectional data diode 215 to a remote system, a sending device 212 at the plant end publishes data across the diode to a receiving device 218 at the remote end. The publication of various data is respectively in accordance with context information (e.g., identification of data sources, respective expected rate of data generation/arrival, etc.) that is descriptive of data sources of the plant, mapped from a configuration that corresponds to the selected process plant data (e.g. to primary, secondary etc. variables) and that is recurrently provided by the sending device across the diode. A recurrence interval may be based on a tolerance for lost data or another characteristic of an application, service, or consumer of data at the remote system. The published data may be converted from a first protocol (e.g., HART-IP) to a second protocol suitable for general-purpose communication (e.g., JSON), with different labels applied (e.g. primary value instead of pressure).