niSwitch_SetAttributeViInt32

NI-SWITCH Functions

niSwitch_SetAttributeViInt32

Specific Function

C Function Prototype

ViStatus niSwitch_SetAttributeViInt32 (ViSession vi, ViConstString channelName, ViAttr attributeID, ViInt32 attributeValue);

Purpose

This function sets the value of a ViInt32 attribute. This is a low-level function that you can use to set the values of instrument-specific attributes and inherent IVI attributes. If the attribute represents an instrument state, this function performs instrument I/O in the following cases:
- State caching is disabled for the entire session or for the
particular attribute.
- State caching is enabled and the currently cached value is
invalid or is different than the value you specify.

This instrument driver contains high-level functions that set most of the instrument attributes. It is best to use the high-level driver functions as much as possible. They handle order dependencies and multithread locking for you. In addition, they perform status checking only after setting all of the attributes. In contrast, when you set multiple attributes using the SetAttribute functions, the functions check the instrument status after each call. Also, when state caching is enabled, the high-level functions that configure multiple attributes perform instrument I/O only for the attributes whose value you change. Thus, you can safely call the high-level functions without the penalty of redundant instrument I/O.

Parameters

Name Type Description
vi ViSession A particular NI-SWITCH session established with niSwitch_InitWithTopology, niSwitch_InitWithOptions, or niSwitch_init and used for all subsequent NI-SWITCH calls.

channelName ViConstString Some attributes are unique for each channel. For these, pass the name of the channel. Other attributes are unique for each switch. Pass VI_NULL or an empty string for this parameter. The default value is an empty string.
attributeID ViAttr Pass the ID of an attribute.

From the function panel window in LabWindows/CVI, you can use this control as follows. Click on the control or press <ENTER>, <spacebar>, or <ctrl-down arrow>, to display a dialog box containing a hierarchical list of the available attributes. Attributes whose value cannot be set are dim. Help text is shown for each attribute. Select an attribute by double-clicking on it or by selecting it and then pressing <ENTER>. Read-only attributes appear dim in the list box. If you select a read-only attribute, an error message appears. A ring control at the top of the dialog box allows you to see all IVI attributes or only the attributes of the ViInt32 type. If you choose to see all IVI attributes, the data types appear to the right of the attribute names in the list box. The data types that are not consistent with this function are dim. If you select an attribute data type that is dim, LabWindows/CVI transfers you to the function panel for the corresponding function that is consistent with the data type. If you want to enter a variable name, press <CTRL-T> to change this ring control to a manual input box. If the attribute in this ring control has constants as valid values, you can view the constants by moving to the Attribute Value control and pressing <ENTER>.

attributeValue ViInt32 Pass the value to which you want to set the attribute. From the function panel window in LabWindows/CVI, you can use this control as follows. If the attribute currently showing in the Attribute ID ring control has constants as valid values, you can view a list of the constants by pressing <ENTER> on this control. Select a value by double-clicking on it or by selecting it and then pressing <ENTER>.
Note  Some of the values might not be valid depending on the current settings of the instrument session.