The NI-FBUS Communications Manager Application Programmer Interface (API)

Note: Writing a program to take advantage of an API is an advanced topic. Most users will not use the provided API.

The API

The NI-FBUS Communications Manager implements a high-level Application Programmer Interface (API) you can use to interface with National Instruments FOUNDATION Fieldbus communications stack and hardware. The main purpose of the NI-FBUS Communications Manager API is to make the details of the FOUNDATION Fieldbus communication protocols transparent to the user. This is achieved by abstracting out all the low-level details involved in interfacing to the Fieldbus Messaging Specification (FMS), lower layers of the communication stack, creation of virtual communication relationships (VCRs), connection management, Fieldbus addressing, and so on. It also provides named access to all Fieldbus devices, Virtual Field Devices (VFDs), function blocks, transducer blocks, and all their parameters.

The NI-FBUS Communications Manager API functions are broadly classified into four categories:

• Administrative Functions -- browse the Fieldbus network and get handles to Fieldbus objects.
• Core Functions -- deal with parameter processing.
• Alert & Trending Functions -- receive alarm & trend data from devices and acknowledge alarms.
• Device Description Functions -- access device descriptions provided by the device manufacturer.
  

The NI-FBUS Communications Manager API allows users to develop host applications that are independent of the actual configuration of their Fieldbus network. Typical examples are configurators, monitoring applications, diagnostic utilities, automated test suites, and developing interfaces to Human Machine Interface (HMI) packages.

Note: The NI-FBUS Communications Manager API alone will not allow you to fully configure a segment. It is generally used to browse the Fieldbus and read and write function block parameter values to a preconfigured segment. See the related link Why Do I Need Configuration Software? for more information on configuring a segment.

See Also:
Why Do I Need Configuration Software?

VIEW objects

Customers using the NI-FBUS Communications Manager API to read multiple parameters will often see better performance if they read pre-defined VIEW objects which contain multiple parameters, rather than reading each parameter individually. NI-FBUS allows explicit access to VIEW objects through its core functions.

See Also:
Using VIEW Objects

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