
©
National Instruments Corporation
4-1
NI-FBUS Hardware and Software User Manual
4
NI-FBUS CM Software
This chapter provides information on the NI-FBUS Communications
Manager (CM) software. It assumes that you are already familiar with your
Microsoft operating system.
NI-FBUS Communications Manager Overview
The NI-FBUS Communications Manager implements a high-level
Application Program Interface (API) that facilitates communication with
the National Instruments F
OUNDATION
™
Fieldbus communication stack and
hardware. The main purpose of the NI-FBUS Communications Manager
is to make the details of the Fieldbus communication protocols transparent
by providing an API that supports
TAG.PARAMETER
access. You need
a general knowledge of the Fieldbus architecture (outlined in the
F
OUNDATION
TM
Fieldbus Overview
document) to understand and use the
NI-FBUS Communications Manager.
The NI-FBUS Communications Manager handles communication between
the communication stack and the user application. It also handles the details
of communicating with the Fieldbus Messaging Specification (FMS) and
lower layers of the communications stack. The NI-FBUS Communications
Manager hides the low-level details of Virtual Communication
Relationships (VCRs), connection management, addresses, and Object
Dictionary indices, and offers name access to physical devices, Virtual
Field Devices (VFDs), function blocks, transducer blocks, and parameters.
The NI-FBUS Communications Manager API is independent of the
National Instruments Fieldbus hardware and your operating system.
With the NI-FBUS Communications Manager, you can plug multiple
National Instruments Fieldbus interfaces of any type into the same PC
and use them through the NI-FBUS Communications Manager API.
NI-FBUS is capable of using the USB-8486, PCMCIA-FBUS, PCI-FBUS,
ControlNet-to-Fieldbus linking devices, Ethernet adapters, and HSE
linking devices as its interface.
The NI-FBUS Communications Manager is interface-independent
because this tool does not require you to specify which Fieldbus interface
to use in NI-FBUS Communications Manager calls. It determines the