5
48-640 E3 Modulevel
®
Displacer Level Transmitter - FOUNDATION fieldbus
™
1.2 Benefits
The benefits of F
OUNDATION fieldbus
™
can be found
throughout all phases of an installation:
1. Design/Installation: Connecting multiple devices to a single
pair of wires means less wire and fewer I/O equipment.
Initial Engineering costs are also reduced because the
Fieldbus Foundation requires interoperability, defined as
“the ability to operate multiple devices in the same system,
regardless of manufacturer, without a loss of functionality.”
All F
OUNDATION fieldbus
™
devices must be tested for
interoperability by the Fieldbus Foundation. Magnetrol
®
E3 MODULEVEL FOUNDATION fieldbus
™
device registration
information can be found at www.fieldbus.org.
2. Operation: With control now taking place within the
devices in the field, better loop performance and control are
the result. A FOUNDATION fieldbus
™
system allows for mul-
tiple variables to be brought back from each device to the
control room for additional trending and reporting.
3. Maintenance: The self-diagnostics residing in the smart
field devices minimizes the need to send maintenance
personnel to the field.
1.3 Device Configuration
Device Descriptions
The function of a FOUNDATION fieldbus
™
device is deter-
mined by the arrangement of a system of blocks defined by
the Fieldbus Foundation. The types of blocks used in a typi-
cal User Application are described as follows:
Resource Block describes the characteristics of the
F
OUNDATION fieldbus
™
device such as the device name,
manufacturer, and serial number.
Function Blocks are built into the F
OUNDATION fieldbus
™
devices as needed to provide the desired control system
behavior. The input and output parameters of function
blocks can be linked over the Fieldbus. There can be
numerous function blocks in a single User Application.
Transducer Blocks contain information such as calibration
parameters and sensor type. They are used to connect the
sensor to the input function blocks.
An important requirement of Fieldbus devices is the inter-
operability concept mentioned earlier. Device Description
(DD) technology is used to achieve this interoperability.
The DD provides extended descriptions for each object and
provides pertinent information needed by the host system.
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