LEC-03 Modules & Function Blocks Rev PDF

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Modules & FBs

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Module Blocks • The concept of the module is fundamental to DeltaV. • The module is the main building block for a system. Modules link the algorithms, displays, I/O, conditions, and other characteristics to the equipment. • Depending on its type, a module can be composed of parameters, a history collection strategy, alarms, conditions, algorithms, and display elements. • These items are bundled together logically as modules so that you can use them in your control strategy.

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Modules Modules are the heart of the DeltaV configuration.

Module

There are fundamentally two categories of modules: Control Modules SFC Modules

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Modules Modules are the heart of the DeltaV configuration.

Module

There are fundamentally two categories of modules: Control Modules SFC Modules Modules contain:  I/O

I/O 03 - Modules &Function Blocks ELEX 4221

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Modules Modules are the heart of the DeltaV configuration.

Module Display References

There are fundamentally two categories of modules: Control Modules SFC Modules Modules contain:  I/O and Display References

I/O 03 - Modules &Function Blocks ELEX 4221

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Modules Modules are the heart of the DeltaV configuration.

Module Display References

There are fundamentally two categories of modules: Control Modules SFC Modules Modules contain:  I/O and Display References  Function Blocks

Function Blocks - Algorithms I/O

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Modules Modules are the heart of the DeltaV configuration.

Module Display References

There are fundamentally two categories of modules: Control Modules SFC Modules

Alarms Modules contain:  I/O and Display References  Function Blocks  Alarms 03 - Modules &Function Blocks ELEX 4221

Function Blocks - Algorithms I/O

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Modules Modules are the heart of the DeltaV configuration.

Module Display References

There are fundamentally two categories of modules: Control Modules SFC Modules

History Collection Alarms

Modules contain:  I/O and Display References  Function Blocks  Alarms and History Collection 03 - Modules &Function Blocks ELEX 4221

Function Blocks - Algorithms I/O

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Modules Modules are the heart of the DeltaV configuration. There are fundamentally two categories of modules: Control Modules SFC Modules Modules contain:  I/O and Display References  Function Blocks  Alarms and History Collection  Parameters 03 - Modules &Function Blocks ELEX 4221

Module P Display References a r History Collection a m Alarms e t Function Blocks e - Algorithms r s

I/O

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Module Blocks • A module is a reusable control algorithm that focuses around process equipment. • Modules link algorithms, conditions, alarms, displays, and other characteristics together for a particular piece of equipment. • The DeltaV system has a library of modules with all the necessary characteristics already defined. • You modify the modules to fit your needs as you develop your control strategies. Refer to the ‘Module Library Reference’ topic in DeltaV Books On Line for more information. 03 - Modules &Function Blocks ELEX 4221

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Module Blocks • Module blocks allow one control module to be represented on the diagram of a different control module (nesting). • This allows the interactions between multiple control strategies to be visually created and maintained while ensuring the isolation and integrity of each independent module. • The module block is graphically wired to other blocks on the strategy. • Control modules typically provide control for a single control element such as a valve. 03 - Modules &Function Blocks ELEX 4221

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Module Blocks • The following figure shows a module block called MODULE with an output parameter that is wired to a splitter function block.

Wires connected to the module automatically establish communications between the module and the splitter function block. Any parameter within the referenced module can be ‘elevated’ so it can be wired. 03 - Modules &Function Blocks ELEX 4221

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Function Blocks • DeltaV utilizes a modular configuration for developing a control strategy. • The control modules (control “packages”) are treated as unique, named control entities in the DeltaV system. • The Function Block is the basic component of a control module, that is, it is the building block of the control module.

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Function Blocks • Each Function Block contains standard process control algorithms (for example: PID, Analog Out, and Analog In blocks). • Advanced process control algorithms are also found in Function Blocks, such as the DeltaV system's fuzzy logic PID. • When wired together in an appropriate and logical sequence, multiple function blocks form a control module.

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Function Blocks Control modules contain Function Blocks.

Module

Function block programming provides an intuitive means of configuring control strategies. Function blocks are typically executed in the controller, however certain function blocks may instead execute in a Foundation Fieldbus device.

P Display References a r History Collection a m Alarms e t Function Blocks e - Algorithms r s

I/O

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Function Blocks • Function Block Diagrams (FBDs) are comprised of individual Function Blocks, Special Palette Items (such as Input/Output Parameters, Internal/External Read/Write Parameters) and Comments. • The figure on the right shows the display structure of a DeltaV Function Block. Function Block Display Structure 03 - Modules &Function Blocks ELEX 4221

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Function Blocks Function Block Icon - the graphical image used to represent a DeltaV function block. Definition name - the name by which this block is known in the DeltaV Function Block Library. It cannot be changed. Usage name - the user defined name for the Function Block. This name must be unique within the module or composite block. It can be changed but be careful… DeltaV Run graphics package relies on default names. 03 - Modules &Function Blocks ELEX 4221

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Function Blocks Parameters - the data used in a function block to perform calculations and logic. The standard connector parameters, which reference wired inputs and outputs of a function block, appear on the block when it is placed on the diagram from the palette. To show other parameters on the block, right click the Function Block and click ‘Show Parameters’. Execution order number - the order in which the function block executes in the module's algorithm. Consult the Control Studio help for information on changing the execution order number. 03 - Modules &Function Blocks ELEX 4221

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Function Blocks Scan multiplier - the number of times the module's algorithm is executed compared to the block. If the scan multiplier is one (this is the default and does not appear on the block), there is a 1:1 ratio, and every time the module scans, the block executes. If the scan multiplier is 3, there is a 1:3 ratio, and the block is executed every third scan. To change the Scan Multiplier, click the right mouse button, and then click Scan Multiplier.

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Function Blocks • Function Block Diagrams are used in DeltaV to implement continuously executing control strategies. • Every block in the diagram is executed each time the module scans. • Graphical wires connect the different blocks within the diagram. Each wire transfers one or more data values from one block to another. • The execution order determines when each block of the diagram executes. 03 - Modules &Function Blocks ELEX 4221

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Function Blocks Sample Function Block Diagram Split Ranging Example

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Function Blocks Sample Function Block Diagram Split Ranging Example

12 – 20 mA

4 – 12 mA

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Function Blocks • The function blocks within the DeltaV system follow the structure specified by the Fieldbus Foundation standard. • A standard group of function blocks come with the DeltaV system and are in the Function Block library. • Additional blocks have been provided to enhance and extend the functionality of the programming language. A set of 46 basic, or primitive, function blocks is available. 03 - Modules &Function Blocks ELEX 4221

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Function Blocks • Function Block Diagrams are built in Control Studio to create or modify algorithms that are defined using function blocks. • Function Blocks are connected together to define how a module behaves.

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Function Blocks Function Block Diagram

Typical single loop PID control configuration 03 - Modules &Function Blocks ELEX 4221

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Function Blocks READ and WRITE Function Blocks Reasons why READ is better than WRITE: • READ ensures that data coming into a module is the “correct” data (not inadvertently being written to from elsewhere in the program) and that the data has “arrived”. • READ sets up an efficient transfer of data between modules and the destination is aware of loss of communications by way of the “status” of the signal. • The destination of a WRITE is unaware if the WRITE doesn’t take place (fails). 03 - Modules &Function Blocks ELEX 4221

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream block. Function block calculates output.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream block. Function block calculates output. • Remote Output (ROUT) – same as Manual but signal comes from remote computer device.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream block. Function block calculates output.

• Remote Output (ROUT) – same as Manual but signal comes from remote computer device.

• Remote Cascade (RCAS) – same as Cascade but signal comes from remote computer device.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream block. Function block calculates output. • Remote Output (ROUT) – same as Manual but signal comes from remote computer device. • Remote Cascade (RCAS) – same as Cascade but signal comes from remote computer device. • Initialization Manual (IMAN) – downstream block not in Cascade.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream block. Function block calculates output.

• Remote Output (ROUT) – same as Manual but signal comes from remote computer device.

• Remote Cascade (RCAS) – same as Cascade but signal comes from remote computer device. • Initialization Manual (IMAN) – downstream block not in Cascade. • Local Override (LO) – Fault condition present. Forces block to known state.

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Function Blocks Function Block Modes • Manual (MAN) - operator determines output. • Automatic (AUTO) – output is calculated by function block. • Cascade (CAS) – input to function block comes from upstream • • • • •

block. Function block calculates output. Remote Output (ROUT) – same as Manual but signal comes from remote computer device. Remote Cascade (RCAS) – same as Cascade but signal comes from remote computer device. Initialization Manual (IMAN) – downstream block not in Cascade. Local Override (LO) – Fault condition present. Forces block to known state. Out of Service (OOS) – Device linked to block has been taken out of service for repair or configuration.

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Function Blocks Function Block Mode Status • Normal Mode The function block’s mode of operation under normal, expected, operating conditions. This mode is set during design/configuration.

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Function Blocks Function Block Mode Status • Normal Mode The function block’s mode of operation under normal, expected, operating conditions. This mode is set during design/configuration.

• Actual Mode The function block’s current mode of operation. This mode cannot be directly written to but is modified by changing the “target” mode.

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Function Blocks Function Block Mode Status • Normal Mode The function block’s mode of operation under normal, expected, operating conditions. This mode is set during design/configuration.

• Target Mode The desired mode for the function block. This may be set by the operator or by logic within the control module(s).

• Actual Mode The function block’s current mode of operation. This mode cannot be directly written to but is modified by changing the “target” mode. 03 - Modules &Function Blocks ELEX 4221

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Composite Blocks User-defined composite blocks improve strategy, readability, and engineering effort. The composite block represents a group of function blocks or SFC (Sequential Function Chart) steps on a diagram. By providing a hierarchical grouping within the module's control diagram, composite blocks enable the following tasks: • segmenting your strategy into logical parts • maintaining common functions in the library while using them many times • intermixing the different control languages within a single module 03 - Modules &Function Blocks ELEX 4221

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Extensible Blocks Many of the standard function blocks are extensible. This capability means you can increase the number of some of the parameters. Function Blocks that are extensible are:  Add,  AND / OR  BFI / BFO  Calc/Logic  Multiply  Multiplexer  Signal Selector. 03 - Modules &Function Blocks ELEX 4221

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Extensible Blocks Example: Standard Add block from the palette has two inputs. To add four values rather than two, extend the number of inputs by selecting the block, right clicking, selecting ‘Extensible Parameters’ and changing the number of inputs from 2 to 4.

Function Block Extensible Parameters Dialog Window 03 - Modules &Function Blocks ELEX 4221

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Extensible Blocks After you increase the number of extensible parameters the additional parameters show on the function block diagram and these can be wired to.

ADD Function Blocks With Input Parameters Increased 03 - Modules &Function Blocks ELEX 4221

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Discrete Input (DI) Function Block

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Discrete Input (DI) Function Block Parameter BLOCK_ERR

Units None

Description The summary of active error conditions associated with the block. The block errors for the Analog Input function block: Out of Service Simulate Active

Input Failure/Bad PV

IO_IN

None

Defines the input DST for the I/O channel used for the PV.

IO_OPTS

None

The supported I/O option for the Analog Input function block is:

MODE

None

Parameter used to show and set the block operating state. MODE contains the actual, target, permitted, and normal modes.

OUT_D

None

The discrete output value and status.

OUT_SCALE

None

SIMULATE_D

None

SIMULATE_IN_D

None

The high and low scale values, engineering units code, and number of digits to the right of the decimal point associated with OUT. Enables simulation and allows you to enter an input value and status when SIMULATE_IN_D is not connected. The simulated discrete input value used when simulation is enabled.

Invert

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Discrete Input (DI) Function Block What does Simulate_D do? What modes are permitted in a DI block? Where does the block’s output signal OUT_D come from in each of the permitted modes?

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Discrete Output (DO) Function Block

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Discrete Output (DO) Function Block Parameter BLOCK_ERR

CAS_IN_D IO_OPTS

Units None

None None

IO_OUT IO_READBACK

None None

MODE

None

OUT_D SIMULATE

None Percent

SP_D

EU of PV_SCALE

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Description The summary of active error conditions associated with the block. The block errors for the Analog Output function block: Out of Service Readback Failed Output Failure Input Failure/Bad PV Simulate Active The remote SP value from another function block. I/O options determine how the I/O si...