The following is a suggested flow of activities for Foundation Fieldbus design in Smart Instrumentation. Note that you can carry out some of the procedures in a different order, depending on your preferences or requirements.
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Define Segment-Wide Parameters for the current site
Segment-wide parameters allow you to define default settings that serve as design rules and limitations for the various Foundation Fieldbus and Profibus PA segments. These parameters affect the function and performance of your fieldbus system in the following ways:
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If you exceed cable lengths, or hook too many devices to the same pair of wires, this can cause attenuation and reduction in the voltage reaching the instruments. These voltage drops can result in instrument malfunction and bandwidth problems.
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If you create a spur cable that is too long, the signal propagated along that spur cable can become attenuated and too weak for the DCS to read.
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If you create a segment whose total capacitance exceeds the maximum, you may reduce effective bandwidth.
For more information, see .
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Define Foundation Fieldbus and Profibus Instrument Type Profiles
Prior to creating new fieldbus instruments, you need to customize wiring reference items and then define appropriate instrument type profiles in the Instrument Index module so that new tag numbers acquire fieldbus properties. This results in automatic assignment of the required properties to the new tag numbers.
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Create a User-Defined Function Block
Because the software does not allow you to modify or delete the shipped function blocks, you can create your own function blocks which you can modify or delete as you see fit. The function blocks that you define here are available for the current site. You can define function blocks as multiple with or without execution time. Instruments can be associated with several function blocks of the same type if that function block is defined as Multiple. Using the Execution Time feature allows you to set the time for the function block execution. You set the number of function blocks and the execution time in the Function Block - Instrument Type Association dialog box. You can create a virtual tag and associate it with an existing function block. Only one virtual tag can be associated with a function block.
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Associate Function Blocks with Instrument Types
Associating function blocks with instrument types enables you to instruct the software to create and associate a particular function block when creating a fieldbus instruments. When you create a fieldbus instrument tag, Smart Instrumentation automatically assigns the function blocks associated with the instrument type that you select for the new tag. Note that you can associate a function block with as many instrument types as required.
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Create Foundation Fieldbus and Profibus Instruments
Create your fieldbus device tags based on the instrument types that you defined, and edit the tag number properties as required, including function block properties. The software allows you to create various types of instruments that can be associated with the Foundation Fieldbus system in your plant. In other words, you can create instruments that are compatible with Foundation Fieldbus, Profibus DP, and Profibus PA segments. You add new instruments in the Instrument Index module, exactly the same way that you create other tags. After you define an instrument type for the new tag number and associate a function block with the new tag's instrument type, the new instrument automatically acquires all of the appropriate properties that you set for that tag number. You can then create virtual tags for this instrument.
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Associate Function Blocks with Instruments
This feature enables you to associate a function block with a particular instrument. You use this feature if for some reason, the current tag number has not been associated with any function block through the tag's instrument type or if you need to change some of the associations. Note that the association or any changes made to the association will affect the current tag number only.
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Create your fieldbus segments and associate them with fieldbus instruments
Now you are ready to create your fieldbus segments, associate the appropriate instruments with their respective segments, and create the necessary virtual tags. For more information, see the following:
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Design your wiring and termination equipment
At this stage you need to create your fieldbus I/O cards and if you are going to use the plug-and-socket communication system, create your fieldbus plug-and-socket boxes. For more details, see the following:
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Add your home-run cables and spurs.
For details, see Fieldbus Cables Common Tasks.
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Making Connections and Associations for Fieldbus
At this stage you are ready to make the required connections and associations. However, before you can associate a segment with a home-run cable or connect a home-run cable to a plug-and-socket box, you need to configure various connector types assign connector pins to wires.
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Generate Fieldbus Validation reports
As you build the segments, and make connections and effect I/O assignments, the software verifies that you are following basic fieldbus rules. Later, you can generate reports to verify that you built the segments according to additional connection rules and according to the segment-wide parameter profiles that you applied to each segment.
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Generate a Segment Wiring Report
You can generate an enhanced segment wiring drawing to view the completed segment.
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Principles of Generating Specifications
In the Specifications module you can associate tags with fieldbus forms to generate specifications.
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If you encounter difficulty in activating a library form for fieldbus, you should restore the form. For details, see Restore Library Forms.
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You can add function block custom fields to fieldbus specifications. For details, see Add Function Block Custom Fields to a Fieldbus Spec.
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You can also generate a hook-up drawing for your fieldbus instruments just like for conventional instruments.