viVxiCommandQuery
Purpose
Sends the device a miscellaneous command or query and/or retrieves the response to a previous query.
C Syntax
ViStatus viVxiCommandQuery(ViSession vi, ViUInt16 mode, ViUInt32 cmd, ViPUInt32 response)
Visual Basic Syntax
viVxiCommandQuery&(ByVal vi&, ByVal mode%, ByVal cmd&, response&)
Resource Classes
GPIB-VXI INSTR, VXI INSTR
Parameters
| Name | Direction | Description |
|---|---|---|
|
vi |
IN |
Unique logical identifier to a session. |
|
mode |
IN |
Specifies whether to issue a command and/or retrieve a response. Refer to the Description section for actual values. |
|
cmd |
IN |
The miscellaneous command to send. |
|
response |
OUT |
The response retrieved from the device. If the mode specifies to send a command rather than retrieve a response, you can use VI_NULL for this parameter. |
Return Values
| Completion Codes | Description |
|---|---|
|
VI_SUCCESS |
The operation completed successfully. |
| Error Codes | Description |
|---|---|
|
VI_ERROR_INV_OBJECT |
The given session reference is invalid. |
|
VI_ERROR_NSUP_OPER |
The given vi does not support this operation. |
|
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 operation completed. |
|
VI_ERROR_RAW_WR_PROT_VIOL |
Violation of raw write protocol occurred during transfer. |
|
VI_ERROR_RAW_RD_PROT_VIOL |
Violation of raw read protocol occurred during transfer. |
|
VI_ERROR_OUTP_PROT_VIOL |
Device reported an output protocol error during transfer. |
|
VI_ERROR_INP_PROT_VIOL |
Device reported an input protocol error during transfer. |
|
VI_ERROR_BERR |
Bus error occurred during transfer. |
|
VI_ERROR_RESP_PENDING |
A previous response is still pending, causing a multiple query error. |
|
VI_ERROR_INV_MODE |
The value specified by the mode parameter is invalid. |
Description
The viVxiCommandQuery() operation can send a command or query, or receive a response to a query previously sent to the device. The mode parameter specifies whether to issue a command and/or retrieve a response, and indicates the type or size of command and/or response to use. The following table defines the values for the mode parameter.
| Mode | Action Description |
|---|---|
|
VI_VXI_CMD16 |
Send 16-bit Word Serial command. |
|
VI_VXI_CMD16_RESP16 |
Send 16-bit Word Serial query; get 16-bit response. |
|
VI_VXI_RESP16 |
Get 16-bit response from previous query. |
|
VI_VXI_CMD32 |
Send 32-bit Word Serial command. |
|
VI_VXI_CMD32_RESP16 |
Send 32-bit Word Serial query; get 16-bit response. |
|
VI_VXI_CMD32_RESP32 |
Send 32-bit Word Serial query; get 32-bit response. |
|
VI_VXI_RESP32 |
Get 32-bit response from previous query. |
Notice that the mode you specify can cause all or part of the cmd or response parameters to be ignored.
- If mode specifies sending a 16-bit command, the upper half of cmd is ignored.
- If mode specifies retrieving a response only, cmd is ignored.
- If mode specifies sending a command only, response is ignored. You can use VI_NULL for the value of response.
- If mode specifies to retrieve a 16-bit value, the upper half of response is set to 0.
Refer to the VXI Specification for defined Word Serial commands.
Related Topics