NI XNET XNET Subframe Properties

XNET Subframe Properties

• Dynamic Signals
• Frame
• Multiplexer Value
• Name (Short)
• Name Unique to Cluster
• PDU

Name (Short)

Data Type	Direction	Required?	Default
char *	Read/Write	Yes	Defined in nxdbCreateObject

Property Class

XNET Subframe

Property ID

nxPropSubfrm_Name

Description

String identifying a subframe object.

Lowercase letters (a–z), uppercase letters (A–Z), numbers, and the underscore (_) are valid characters for the short name. The space ( ), period (.), and other special characters are not supported within the name. The short name must begin with a letter (uppercase or lowercase) or underscore, and not a number. The short name is limited to 128 characters.

A subframe name must be unique for all subframes in a frame.

This short name does not include qualifiers to ensure that it is unique, such as the database, cluster, and frame name. It is for display purposes.

You can write this property to change the subframe's short name.

Dynamic Signals

Data Type	Direction	Required?	Default
nxDatabaseRef_t *	Read Only	N/A	N/A

Property Class

XNET Subframe

Property ID

nxPropSubfrm_DynSigRefs

Description

Dynamic signals in the subframe.

This property returns an array of references to dynamic signals in the subframe. Those signals are transmitted when the multiplexer signal in the frame has the multiplexer value defined in the subframe.

Dynamic signals are created with nxdbCreateObject by specifying a subframe as the parent.

Frame

Data Type	Direction	Required?	Default
nxDatabaseRef_t	Read Only	N/A	N/A

Property Class

XNET Subframe

Property ID

nxPropSubfrm_FrmRef

Description

Returns the reference to the parent frame. The parent frame is defined when the subframe is created, and you cannot change it afterwards.

Multiplexer Value

Data Type	Direction	Required?	Default
u32	Read/Write	Yes	N/A

Property Class

XNET Subframe

Property ID

nxPropSubfrm_MuxValue

Description

Multiplexer value for this subframe.

This property specifies the multiplexer signal value used when the dynamic signals in this subframe are transmitted in the frame. Only one subframe is transmitted at a time in the frame.

There also is a multiplexer value for a signal object as a read-only property. It reflects the value set on the parent subframe object.

This property is required. If the property does not contain a valid value, and you create an XNET session that uses this subframe, the session returns an error. To ensure that the property contains a valid value, you can do one of the following:

• Use a database file (or alias) to create the session.

  The file formats require a valid value in the text for this property.

• Set a value using the nxdbSetProperty function.

  This is needed when you create your own in-memory database (:memory:) rather than use a file. The property does not contain a default in this case, so you must set a valid value prior to creating a session.

PDU

Data Type	Direction	Required?	Default
nxDatabaseRef_t	Read Only	N/A	N/A

Property Class

XNET Subframe

Property ID

nxPropSubfrm_PDURef

Description

Reference to the subframe's parent PDU.

This property returns the reference to the subframe's parent PDU. The parent PDU is defined when the subframe object is created. You cannot change it afterwards.

Name Unique to Cluster

Data Type	Direction	Required?	Default
string	Read Only	N/A	N/A

Property Class

XNET Subframe

Property ID

nxPropSubfrm_NameUniqueToCluster

Description

This property returns a subframe name unique to the cluster that contains the subframe. If the single name is not unique within the cluster, the name is ..

You can pass the name to the nxdbFindObject function to retrieve the reference to the object, while the single name is not guaranteed success in nxdbFindObject because it may be not unique in the cluster.