CNVGetDataFromBuffer
int CNVGetDataFromBuffer (CNVBufferedSubscriber bufferedSubscriber, CNVData *data, CNVBufferDataStatus *dataStatus);
Purpose
Gets the next buffered value of a network variable using a buffered subscriber connection.
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Note This function is not reliable when the system or variable engine has just started up. This function can only check if the network variable process is configured to run, and so, during system startup may return TRUE even though the network variable process is not fully available. If your program needs to check if a network variable process is available during system startup, National Instruments recommends using the CNVBrowse function to browse the network variable process. |
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Note To avoid deadlocks, do not call this function in a network variable callback function. |
Parameters
| Input | ||||||||||
| Name | Type | Description | ||||||||
| bufferedSubscriber | CNVBufferedSubscriber | The handle that identifies the network variable buffered reader connection. | ||||||||
| Output | ||||||||||
| Name | Type | Description | ||||||||
| data | CNVData | Handle of the network variable data. Call CNVDisposeData to dispose the handle when you are done using it. CNVGetDataFromBuffer returns zero if there is no data in the buffer. | ||||||||
| dataStatus | CNVBufferDataStatus | The status of the network variable data. You can pass NULL if you do not want this information. The status can be one of the following values.
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Return Value
| Name | Type | Description |
| status | int | Return value indicating whether the function was successful. One indicates that a next item was found, zero indicates that a next item was not found, and a negative number indicates that an error occurred. You can call CNVGetErrorDescription to obtain a string that describes the error. |
Additional Information
Library: Network Variable Library
Include file: cvinetv.h
LabWindows/CVI compatibility: LabWindows/CVI 8.1 and later
Examples
Refer to the following examples that use the CNVGetDataFromBuffer function:
- networkvariable\Buffering\NVBuffering.cws
Open example - networkvariable\Polling\NVPolling.cws
Open example