Creates a new NI-DCPower session to the specified instrument(s) and channel(s) and returns a session handle to be used in all subsequent NI-DCPower function calls.

Syntax

ViStatus _VI_FUNC niDCPower_InitializeWithIndependentChannels(ViRsrc resourceName, ViBoolean reset, ViConstString optionString, ViSession *vi)

Remarks

After calling this function, the specified channel or channels will be in the Uncommitted state.

With this function and channel-based NI-DCPower functions and attributes, you can use any channels in the session independently. For example, you can initiate a subset of channels in the session with niDCPower_InitiateWithChannels, and the other channels in the session remain in the Uncommitted state.

Details

Details of Independent Channel Operation

When you initialize with independent channels, each channel steps through the NI-DCPower programming state model independently of all other channels, and you can specify a subset of channels for most operations.

Note

You can make concurrent calls to a session from multiple threads, but the session executes the calls one at a time. If you specify multiple channels for a function or attribute, the session may perform the operation on multiple channels in parallel, though this is not guaranteed, and some operations may execute sequentially.

Related Topics:

Programming States

Parameters

NameDirectionTypeDescription
resourceName[in]ViRsrc

Specifies the NI-DCPower resources to use in the session. NI-DCPower resources can be names of the instrument(s) assigned by Measurement & Automation Explorer (MAX) and the channel(s) to initialize. Specify the instrument(s) and channel(s) using the form PXI1Slot3/0,PXI1Slot3/2-3,PXI1Slot4/2-3 or PXI1Slot3/0,PXI1Slot3/2:3,PXI1Slot4/2:3, where PXI1Slot3 and PXI1Slot4 are instrument resource names and 0, 2, and 3 are channels.

If you pass "" for this control, all channels of the instrument(s) are included in the session.

reset[in]ViBoolean

Specifies whether to reset channel(s) during the initialization procedure. The default is VI_FALSE.

To place channel(s) in a known startup state when creating a new session, set reset to VI_TRUE. This action is equivalent to using the niDCPower_ResetWithChannels function immediately after initializing the session.

To open a session and leave the channel(s) in an existing configuration without passing through a transitional output state, set reset to VI_FALSE. Next, configure the channel(s) as in the previous session, change the desired settings, and then call the niDCPower_InitiateWithChannels function to write both settings.

optionString[in]ViConstString

Specifies the initial value of certain attributes for the session. The syntax for optionString is a list of attributes with an assigned value where 1 is VI_TRUE and 0 is VI_FALSE. For example:

Simulate=0, DriverSetup=Model:<model number>; BoardType:<bus connector>

To simulate a multi-instrument session, set Simulate to 1 and list multiple instruments for DriverSetup. For example:

Simulate=1, DriverSetup=ResourceName:<instrument name>; Model:<model number>; BoardType:<bus connector> & ResourceName:<resource name>; Model:<model number>; BoardType:<bus connector>

You do not have to specify a value for all the attributes. If you do not specify a value for an attribute, the default value is used.

For more information about simulating a device, refer to Simulating an Instrument.

vi[out]ViSession *

Returns a session handle that you use to identify the session in all subsequent NI-DCPower function calls.

Returns

Reports the status of this operation. To obtain a text description of the status code, call niDCPower_error_message. To obtain additional information concerning the error condition, call niDCPower_GetError. The general meaning of the status code is as follows:

Value

Meaning

0

Success

Positive Values

Warnings

Negative Values

Errors