Parameter data types

Parameter data can be transmitted between blocks and used for trending, alarming, diagnostics, and advanced control. Outputs from one function block can be brought into another function block as parameters for calculation or logic functions and sent to other function blocks or to the field.

Function block parameter data can be one of the following types:

Boolean — a logic value that is True (1) or False (0).
Boolean with Status — a True or False value with status indicator.
Discrete with Status — an unsigned 8-bit integer value with a status indicator. A value of 0 (zero) means False. A value between 1 and 255 means True.
Simulate Discrete — a discrete value that enables/disables simulation and a simulated discrete value and status.
Dynamic Reference — a type of external parameter used to define a path to a value selected at run time.
External Reference — a reference to a parameter outside the current module.
Floating Point — a number whose decimal point location is not fixed. This allows the calculation to consider significant digits information.
Floating Point Array — an aggregate of floating point values.
Floating Point with Status — a floating point value with a status indicator.
Simulate Float — a discrete value that enables/disables simulation and a simulated floating point value and status.
I/O Reference — a value that assigns channel names in an I/O device.
Integer — a whole number. A signed integer has a positive or negative sign associated with it; an unsigned integer does not. Integer values can be 8-, 16-, or 32-bit values.
Internal Reference — a reference to a parameter within the current module.
Mode — a collection of bitstrings that describe the target, actual, permitted, and normal modes of a block.
Named Set — a value from 0 to 255 that displays an assigned text message.
Option Bitstring — an unsigned 16-bit value that indicates the chosen options.
Scaling — a number that is used to convert a floating point value to the required engineering units.
String — as many as 255 characters. Recipe parameters limit string values to 60 characters.

You view the data type of each parameter by expanding the Parameter View window in Control Studio.

Because data of different types can be transmitted between function blocks, there are rules that govern data compatibility and conversions. The data conversions are performed automatically by the DeltaV software.

Data types that have a status associated with them are treated in one of three ways, depending on the conversion:

When a data type with a status field is converted to another data type with a status field, the status field is copied from one to the other.
When a data type with a status field is converted to a data type without a status field, the status field is lost.
When a data type without a status field is converted to one with a status field, a Good status field is created.

Note

If the source parameter value becomes a value that cannot be converted to the target data type (for example, a signed integer wired to an unsigned integer becomes negative), the target value retains the last converted value.

The following table lists parameter data type compatibility information:

Table: Function block parameter compatibility
Parameter Data Type	Accepted Links	Comments
8-bit Signed Integer	8-bit Signed Integer	Bit copy full parameter.
	16-bit Signed Integer	Current value converted; no data loss.
	32 bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer with status	Current value converted; clamped to extremes of destination type.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
16-bit Signed Integer	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Bit copy full parameter.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer with status	Current value converted; clamped to extremes of destination type.
	Floating Point	Current value converted; no data loss.
	Floating Point with Status	Current value converted; no data loss.
	Discrete with Status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with Status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
32-bit Signed Integer	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	32-bit Signed Integer	Bit copy full parameter.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer with status	Current value converted; clamped to extremes of destination type.
	Floating Point	Current value converted; precision loss.
	Floating Point with status	Current value converted; precision loss.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
8-bit Unsigned Integer	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; no data loss.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Bit copy full parameter.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with Status	Current value converted; no data loss.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Current value converted; no data loss.
16-bit Unsigned Integer	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Bit copy full parameter.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Current value converted; clamped to extremes of destination type.
32-bit Unsigned Integer	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	32-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer	Bit copy full parameter.
	32-bit Unsigned Integer with status	Current value converted; clamped to extremes of destination type.
	Floating Point	Current value converted; precision loss.
	Floating Point with status	Current value converted; precision loss.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
32-bit Unsigned Integer with status	8-bit Signed Integer	Current value set to zero if source current value equals zero. Else, current value set to one.
	16-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	32-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	32-bit Unsigned Integer with status	Bit copy full parameter.
	Floating Point	Current value converted; precision loss.
	Floating Point with status	Current value converted; precision loss.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
Boolean	8-bit Signed Integer	Current value converted; no data loss.
	16-bit Signed Integer	Current value converted; no data loss.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; no data loss.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Current value converted; no data loss.
	Boolean	Bit copy full parameter.
	Boolean with status	Current value converted; no data loss.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Current value converted; no data loss.
Boolean with status	8-bit Signed Integer	Current value converted; no data loss.
	16-bit Signed Integer	Current value converted; no data loss.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; no data loss.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Current value converted; no data loss.
	Boolean	Current value converted; no data loss.
	Boolean with status	Bit copy full parameter.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Current value converted; no data loss.
Floating Point	8-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	16-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	8-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	16-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Unsigned Integer with status	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	Floating Point	Bit copy full parameter.
	Floating Point with status	Current value converted; clamped to extremes of destination type.
	Discrete with status	Current value converted; clamped to extremes of destination type.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
Floating Point with status	8-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	16-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Signed Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	8-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	16-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Unsigned Integer	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	32-bit Unsigned Integer with status	Current value converted. If the number to be converted is larger than the extremes of the destination type, the previous converted value is retained.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Bit copy full parameter.
	Discrete with status	From 0 to 255, the current value is converted to integer. If the current value becomes greater than 255, the converted value remains at its previous value.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; clamped to extremes of destination type.
	Named Set	Current value converted; clamped to extremes of destination type.
Floating Point Array	Floating Point Array	Compatible only when dimensions match exactly. Bit copy full parameter.
Simulate Float	None
Discrete with status	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; no data loss.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; no data loss.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Bit copy full parameter.
	Mode	Current value converted into Target Mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Current value converted; no data loss.
Simulate Discrete	None
Option Bitstring	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; clamped to extremes of destination type.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	From 0 to 255, the current value is converted to integer. If the current value becomes greater than 255, the converted value remains at its previous value.
	Mode	Current value converted into target mode.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Bit copy full parameter.
	Named Set	Current value converted; clamped to extremes of destination type.
Scaling	Scaling	Bit copy full parameter.
Mode	8-bit Signed Integer	Actual mode converted into current value.
	16-bit Signed Integer	Actual mode converted into current value.
	32-bit Signed Integer	Actual mode converted into current value.
	8-bit Unsigned Integer	Actual mode converted into current value.
	16-bit Unsigned Integer	Actual mode converted into current value.
	32-bit Unsigned Integer	Actual mode converted into current value.
	32-bit Unsigned Integer with status	Actual mode converted into current value.
	Floating Point	Actual mode converted into current value.
	Floating Point with status	Actual mode converted into current value.
	Discrete with status	Actual mode converted into current value.
	Mode	Bit copy full parameter.
	Option Bitstring	Actual mode converted into current value.
	Named Set	Actual mode converted into current value.
Access Permissions	None
I/O Reference	None
Named Set	8-bit Signed Integer	Current value converted; clamped to extremes of destination type.
	16-bit Signed Integer	Current value converted; no data loss.
	32-bit Signed Integer	Current value converted; no data loss.
	8-bit Unsigned Integer	Current value converted; no data loss.
	16-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer	Current value converted; no data loss.
	32-bit Unsigned Integer with status	Current value converted; no data loss.
	Boolean	Current value set to zero if source current value equals zero. Else, current value set to one.
	Floating Point	Current value converted; no data loss.
	Floating Point with status	Current value converted; no data loss.
	Discrete with status	Current value converted; no data loss.
	Mode	Current value converted into target mode.
	Boolean with status	Current value set to zero if source current value equals zero. Else, current value set to one.
	Option Bitstring	Current value converted; no data loss.
	Named Set	Bit copy plus pointer duplication. Set strings must match.

Related information

Floating point parameter

Dynamic Reference Parameter

External Reference Parameter

Internal Reference Parameter