Configuring the I/O Feature

Read

(not applicable)

Select to add a Read (input) attribute to the object.

None

Read/Write

(not applicable)

Select to add Read and Write (input/output) attributes to the object.

None

Write

(not applicable)

Select to add a Write (output) attribute to the object.

None

Read from

InputSource

Available when the Read option is selected to add an input attribute to the object. The attribute reads its value from an external destination, which by default is set to use IO auto assignment. In the IDE, the default value is <IODevice>.[Object]. [Attribute]. When the objectis assigned to a scan group, the value will resolve.

If changed at run time, the new reference will be registered as an override.

Supervisory, User

Write to

OutputDest

Available when the Write option is selected to add an output attribute to the object. The attribute writes its value to an external destination, which by default is set to use IO auto assignment. In the IDE, the default value is <IODevice>.[Object]. [Attribute]. When the object is assigned to a scan group, the value will resolve.

If changed at run time, the new reference will be registered as an override.

Supervisory, User

Read from/Write to

InputSourceOutputDest

Available when the Read/Write option is selected to add both input and output attributes to the object and "Output destination differs from input source" is not selected.

Supervisory, User

Output destination differs from input source

DiffOutputDest

Select if the output destination is different from the input source.

None

Buffered

HasBuffer

The buffered data feature enables efficient accumulation and propagation of VTQ (Value, Time, and Quality) data updates, without folding and data loss, to data consumers such as objects, alarms, the Historian, and scripts from field devices that support buffering.

None

Deadband

Deadband

Enter a valid double value. Deadband is the range within which an input can be varied without initiating an observable response.

Read-Only

Reflect input to output

Available only when I/O is configured as Read/Write.

None

Output every scan

OutputEveryScan

If selected, the external output is performed every scan (as long as the attribute's quality is Good or Uncertain).

If this check box is cleared, the external output is only performed when the value changes from the last successful output, or when the quality changes from Bad (or Initializing) to Good (or Uncertain), even if the value has not changed.

Supervisory, User

Enable I/O Scaling

Scaled

Used to enable scaling between the raw value and the EU value.

If enabled, you can define the maximum and minimum values (Raw or Engineering Units) for an attribute before it is either clamped (if clamping enabled) or declared not-a-number (NaN).

When enabled, the following scaling attributes become available.

None

Raw value - Minimum
(Scaling)

RawMin

The raw input minimum to be used in the scaling calculation.

Supervisory, User

Raw value - Maximum
(Scaling)

RawMax

The raw input maximum to be used in the scaling calculation.

Supervisory, User

EU value - Minimum
(Scaling)

EngUnitsMin

The minimum value, in engineering units, used in the scaling calculation.

Supervisory, User

EU value - Maximum
(Scaling)

EngUnitsMax

The maximum value, in engineering units, used in the scaling calculation.

Supervisory, User

Extended EU range - Minimum
(Scaling)

EngUnitsRangeMin

The lowest allowed scaled value for the Attribute before it is clamped, if clamping is enabled. This value must be less than or equal to the specified minimum engineering unit value.

With square root conversion mode selected, EngUnitsRangeMin is not configurable and is set equal to the EngUnitsMin attribute.

If the returned value is less than the value set for EngUnitsRangeMin:

• If NOT clamped, the value is reported with BAD quality.

• If clamped, the value will equal EngUnitsRangeMin with Uncertain quality.

Supervisory, User

Extended EU range - Maximum
(Scaling)

EngUnitsRangeMax

The highest allowed scaled value for the Attribute before it is clamped, if clamping is enabled. This value must be greater than or equal to the specified maximum engineering unit value.

With square root conversion mode selected, EngUnitsRangeMax is not configurable and is set equal to the EngUnitsMax attribute.

If the returned value is greater than the value set for EngUnitsRangeMax:

• If NOT clamped, the value is reported with BAD quality.

• If clamped, the value will equal EngUnitsRangeMax with Uncertain quality.

Supervisory, User

Conversion mode

Conversion
Mode

Used to specify either Linear or Square root for the equation that will be used to scale the input

If Square root is selected, the raw value is clamped to the MinRaw and MaxRaw value range before the Square root conversion is executed.

The Quality will be set to the following: BAD quality if the raw value has BAD quality, to INITIALIZING quality if the raw value has INITIALIZING quality, and to GOOD quality otherwise.

Read-Only

Clamp input to EU range
(Scaling)

Clamp
Enabled

Used to allow the scaling process to clamp the engineering unit result.

If clamping is enabled, the scaling calculation result is clamped at either the maximum engineering unit range value or the minimum engineering unit range value, and attribute quality is set to UNCERTAIN.

If not clamped, and the Attribute value exceeds the engineering unit range, then the value will continue to scale out of range, and the quality is set to BAD.

If Square root conversion is selected, ClampEnabled is not configurable.

Supervisory, User