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Device Services

The Device Services page is the visible, editable catalog of the protocol families and reference EdgeX device services NereidLink knows how to render structured forms for.

What the catalog is

Each catalog entry (a protocol family) records:

  • Family key — the open-vocabulary protocol family stored on a device profile, e.g. s7, modbus.
  • Display name and service name — the reference EdgeX device service (e.g. device-s7) used to seed a blank connector template's ds_name.
  • Protocol key / transports — the concrete keys that may appear under an EdgeX device's protocols map (e.g. s7, modbus-tcp).
  • Connection parameters — structured fields rendered in the profile/device connector editor and emitted verbatim into the protocol property map.
  • Point address parameters — structured fields rendered per point descriptor and emitted into the point address object.
  • Default point address — the initial address object prefilled when a new point is created (e.g. {"NodeName": "DB4.DBX0.0"}). Leave it empty to derive defaults from each parameter's own default value.
  • A link to the official documentation.

The catalog is global: the same vendor facts apply to every tenant. The platform kernel itself parses no protocol; the catalog only drives UI forms and suggestions. Ingestion and parsing stay transport-independent.

Built-in vs custom

  • The fourteen device services listed by the EdgeX 4.0.2 device-service index are seeded as Official entries: Modbus, ONVIF camera, MQTT, REST, device-virtual, SNMP, BACnet, CoAP, GPIO, OPC-UA, RFID LLRP, S7, UART and USB camera.
  • Official entries can be edited (to correct a label, add a field) but cannot be deleted.
  • Use Add device service to define a custom family; custom entries can be edited and deleted.

How it relates to device profiles

Selecting a profile's protocol family unlocks that family's structured connection parameters (on the connector template and gateway connector instance) and point-address fields (on each descriptor). Families with no fixed properties, or families not in the catalog, fall back to free JSON editing; unknown content is never rejected.

S7 notes

  • device-s7 speaks ISO-on-TCP. Connection properties are Host, Port (102), Rack, Slot and Timeout/IdleTimeout as integer seconds (not duration strings).
  • A point address uses a single attribute NodeName, e.g. DB4.DBX0.0, DB4.DBD4.
  • A pasted EdgeX device profile whose resources carry NodeName is auto-tagged family s7. A gateway-reported minimal frame that omits attributes cannot be auto-tagged until the edge includes them.