Flowserve MX FOUNDATION Fieldbus Field Unit Manual de usuario descargar pdf (Pagina 38)

MX/QX FOUNDATION Fieldbus Field Unit FCD LMENIM2330-01 – 08/11

3.8 Transducer Block

The custom transducer block is the interface between the function blocks and the rest of the MX/QX

FF ﬁeld unit. It provides all the connections to the actuator itself and contains within its parameters all

the information about the Foundation device, commands, and data feedback. This block is custom-

ized, and the links between the hardware and block are already made to allow the user to access

deﬁned settings for the device.

Many of the links between the Transducer block and the Input/Output blocks are also deﬁned and

may not be altered. Data may be read from the parameters but not all parameters permit write

commands. Writes are limited to the parameters used to set up the actuator control functions.

Some of the Transducer block parameters represent multiple conditions for the state of the actuator.

The tables in Appendix B give a full list of the available parameters.

3.9 Device Description and Capabilities Files

Device Descriptions (DDs) provide an extended description of the data in a device. DDs and

Capabilities Files are obtained from the Fieldbus Foundation: www.ﬁeldbus.org.

The DDs are written in a standard Device Description Language (DDL) to provide an extended

descripton of the ﬁeld device capabilities and names. A DD can be thought of as a driver for the

device. The Link Active Scheduler (LAS) interprets these DDs to see and use the ﬁeld devices.

For each device, the device description deﬁnes the format of its data:

• Tag name

• Parameter labels

• Parameter relationships

• Coding and how many decimal points to display

• Engineering units

• Calibration and diagnostic menus

• Help text

The host interprets these descriptions and provides views to allow efﬁcient communication of

common group parameters. There is easy access to parameters for:

• Face plate HMI

• Loop tuning

• Conﬁguration changes A Capabilities File describes the communication objects in a ﬁeldbus device.

A conﬁguration device can use Device Description (DD) ﬁles and Capabilities ﬁles to conﬁgure a

ﬁeldbus system without having the ﬁeldbus devices online. The ﬁles provide the following:

• Proﬁle information

• Actual number of Function Blocks inside the device

• Function Block timing

• Example communication and function block data

• Host system needs for ofﬂine conﬁguration

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Flowserve MX FOUNDATION Fieldbus Field Unit Manual de usuario Pagina 38