viBufRead
Syntax
viBufRead(ViSession vi, ViPBuf buf, ViUInt32 count, ViPUInt32 retCount);
Description
Similar to viRead, except that the operation uses the formatted I/O read buffer for holding data read from the device. This operation is similar to viRead and does not perform any kind of data formatting. It differs from viRead in that the data is read from the formatted I/O read buffer (the same buffer as used by viScanf and related operations) rather than directly from the device. This operation can intermix with the viScanf operation, but use with the viRead operation is discouraged.
Parameters
|
Name |
Dir |
Type |
Description |
|---|---|---|---|
|
vi |
IN |
ViSession |
Unique logical identifier to a session. |
|
buf |
OUT |
ViPBuf |
Represents the location of a buffer to receive data from the device. |
|
count |
IN |
ViUInt32 |
Number of bytes to be read. |
|
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 |
|
|
Action 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 Code |
Description |
|---|---|
|
VI_SUCCESS |
The operation completed successfully and the END indicator was received (for interfaces that have END indicators). |
|
VI_SUCCESS_MAX_CNT |
The number of bytes read is equal to count |
|
VI_SUCCESS_TERM_CHAR |
The specified termination character was read. |
|
Error Code |
Description |
|
VI_ERROR_INV_SESSION |
The given session or object reference is invalid (both are the same value). |
|
VI_ERROR_IO |
An unknown I/O error occurred during transfer. |
|
VI_ERROR_NSUP_OPER |
The given vi does not support this function. |
|
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. |