viWrite
Syntax
viWrite(ViSession vi, ViBuf buf, ViUInt32 count, ViPUInt32 retCount);
Description
This function synchronously transfers data to a device. The data to be written is in the buffer represented by buf. This function returns only when the transfer terminates. Only one synchronous write function can occur at any one time. If you pass VI_NULL as the retCount parameter to the viWrite operation, the number of bytes transferred will not be returned. This may be useful if it is important to know only whether the operation succeeded or failed.
Note: If you are using viWrite in Visual Basic 6, see Notes on Using viRead/viWrite in Visual Basic 6 for information on modifying its declaration to allow efficient reading and writing of numeric arrays.
Parameters
|
Name |
Dir |
Type |
Description |
|
vi |
IN |
ViSession |
Unique logical identifier to a session. |
|
buf |
IN |
ViBuf |
Represents the location of a data block to be sent to device. |
|
count |
IN |
ViUInt32 |
Specifies number of bytes to be written. |
|
retCount |
OUT |
ViPUInt32 |
Represents the location of an integer that will be set to the number of bytes actually transferred. |
|
Special Value for retCount Parameter |
|||
|
Value |
|
|
Description |
|
VI_NULL |
|
|
Do not return the number of bytes transferred. |
Return Values
|
Type ViStatus |
This is the function return status. It returns either a completion code or an error code as follows. |
|
Completion Codes |
Description |
|
VI_SUCCESS |
Transfer completed. |
|
Error Codes |
Description |
|
VI_ERROR_BERR |
Bus error occurred during transfer. |
|
VI_ERROR_CONN_LOST |
The I/O connection for the given session has been lost. |
|
VI_ERROR_INP_PROT_VIOL |
Device reported an input protocol error occurred during transfer. |
|
VI_ERROR_INV_SESSION |
The given session or object reference is invalid (both are the same value). |
|
VI_ERROR_INV_SETUP |
Unable to start write function because setup is invalid (due to attributes being set to an inconsistent state). |
|
VI_ERROR_IO |
Unknown I/O error occurred during transfer. |
|
VI_ERROR_NCIC |
The interface associated with the given vi is not currently the controller in charge. |
|
VI_ERROR_NLISTENERS |
No Listeners condition is detected (both NRFD and NDAC are de-asserted). |
|
VI_ERROR_NSUP_OPER |
The given vi does not support this function. |
|
VI_ERROR_RAW_RD_PROT_VIOL |
Violation of raw read protocol occurred during transfer. |
|
VI_ERROR_RAW_WR_PROT_VIOL |
Violation of raw write protocol occurred during transfer. |
|
VI_ERROR_RSRC_LOCKED |
Specified operation could not be performed because the resource identified by vi has been locked for this kind of access. |
|
VI_ERROR_TMO |
Timeout expired before function completed. |
See Also
viRead
Notes on Using viRead/viWrite in Visual Basic 6