Rockwell Automation 1788-FFCT NI-FBUS Configurator User Manual - Manual (Page 18)

Publication 1788-UM052B-EN-P - April 2002
2-2 Configuring a Fieldbus System
3. Set addresses and tags.
• Each device has a physical device tag and a fieldbus network
address. You must assign a unique tag to each device. Each
address must be unique within a fieldbus segment.
• Each device has function blocks that perform control
functions, such as AI, AO, DI, DO, PID, and so on. Devices
also have transducer blocks that perform I/O with sensors
and actuators. You must assign a unique tag to function and
transducer blocks.
For instructions on how to set addresses and tags, refer to the
Setting Device or Block Tags and Setting Device Addresses
sections on pages 4-5 and 4-6, respectively.
4. Formulate a control strategy.
• To define your control strategy, identify the function blocks
and connect the relevant function blocks. For example, if you
are configuring a cascaded PID control, you must identify the
primary and secondary PIDs and their inputs and outputs.
• You must also configure loop times or cycle times. For
example, you can configure the primary loop in the cascade
to execute at a certain rate, and configure the secondary loop
to execute at a different rate.
For instructions on how to formulate a control strategy, refer to
the Formulating a Control Strategy section on page 4-8.
5. Schedule function blocks and communication.
Fieldbus schedules the execution of function blocks and the
communication between the connected function blocks. The
two schedules are synchronized to prevent oversampling.
For instructions on how to edit the schedule, Viewing and
Editing a Schedule section on page 4-27.