Block descriptions, Block parameter column descriptions – Flowserve 400MD Logix User Manual

Page 31

Advertising
background image

Table 8.1 Function Block Application Process Elements

Block Type

Function

Resource

Contains data which describes the hardware (physical) characteristics of the device. The

resource block does not perform any action, but contains parameters that support application

downloads.

Main Transducer

Transducer blocks Isolate the function blocks from I/O devices such as sensors, actuators,

and switches. The transducer block interfaces with the hardware to produce an output. It also

contains device-specific parameters, such as calibration and diagnostics parameters.

The main transducer block contains all of the parameters/data required for basic functionality

of the device

Tech Transducer

The tech transducer block contains parameters/data that can be used to troubleshoot or

analyze the device.

MD Transducer

The MD transducer block contains parameters/data that are associated with the advanced or

pro diagnostics of the device.

Analog Output (AO) function block

Performs basic automation functions that are integral to automated control and processing

operations. The AO block performs functions like engineering units scaling, output scaling,

alarming, and back calculation, when connected as a cascade to a PID or other block

Digital Output (DO) function block

The DO block converts the value in SP_D to something useful for the hardware found at the

CHANNEL selection.

Digital Input (DI) function block

The DI block takes the manufacturer’s discrete input data, selected by channel number, and

makes it available to other function blocks at its output.

Input Selector (IS) function block

This block is intended to be used in a forward path only and is not intended to receive signals

from the output of a controller. There is no back calculation support or propagation of control

status values.

Output Splitter (OS) function block

PID Controller function block

Performs standard or robust proportional integral derivative algorithm used in closed-loop

processing.

Figure 8.1 FBAP Block Diagram Example

Block Descriptions

Each block contains parameters that are standard Fieldbus Foundation-defined parameters. In other words, the parameters are pre-defined
as part of the FF protocol for all fieldbus devices. Additionally, parameters exist which are defined by Flowserve and are specific to the Valtek
Logix 3400MD digital positioner.

The following block descriptions list the predefined FF parameters included as part of the block as well as the Flowserve-defined parameters. A
complete description for the FF parameters is provided in the Fieldbus Foundation document FF-891, Foundation Specification Function Block
Application Process Part 2. The Flowserve parameter descriptions are included here as part of the block descriptions.

Block Parameter Column Descriptions

Tables on the following pages list all of the block parameters contained in each of the block objects. Table 8.2 explains the column headings
for the parameter listings.

Resource

Block

PID Block

IN

OUT

BKCAL_IN

Resource

Communication Stack

Algorithm

AO Block

Scaling

CAS_IN

BKCAL_OUT

OUT

Transducer

Block

channel

Value

read/write

read/write

read/write

read/write

Subscribe

Logix

Positioner

Circuitry

Logix 3400MD Digital Positioner LGENIM3405-02 11/13

31

Advertising