« Close

Datasheets and User Guides

App Notes

Software & Driver

 

4.2.8 - GetResult()

Calling either Go function creates a list of results that matches the list of requests. Use GetResult() to read the result and errorcode for a particular IOType and Channel. Normally this function is called for each associated AddRequest() item. Even if the request was an output, the errorcode should be evaluated.

None of the Get functions will clear results from the list. The first AddRequest() call subsequent to a Go call will clear the internal lists of requests and results for a particular device.

When processing raw in/out or stream data requests, the call to a Get function does not actually cause the data arrays to be filled. The arrays are filled during the Go call (if data is available), and the Get call is used to find out many elements were placed in the array.

GetResultS() is a special version of the Get function where IOType is a string rather than a long. This is useful for passing string constants in languages that cannot include the header file, and is generally used with all IOTypes except put/get config. The string should contain the constant name as indicated in the header file (such as “LJ_ioANALOG_INPUT”). The declaration for the S version of Get is the same as below except for (…, const char *pIOType, …).

GetResultSS() is a special version of the Get function where IOType and Channel are strings rather than longs. This is useful for passing string constants in languages that cannot include the header file, and is generally only used with the put/get config IOTypes. The strings should contain the constant name as indicated in the header file (such as “LJ_ioPUT_CONFIG” and “LJ_chLOCALID”). The declaration for the SS version of Get is the same as below except for (…, const char *pIOType, const char *pChannel, …).

It is acceptable to pass NULL (or 0) for any pointer that is not required.

Declaration:

LJ_ERROR _stdcall GetResult (  LJ_HANDLE Handle,
                               long IOType,
                               long Channel,
                               double *pValue)

Parameter Description:
Returns: LabJack errorcodes or 0 for no error.
Inputs:

  • Handle – Handle returned by OpenLabJack().
  • IOType – The type of request. See Section 4.3 (UE9, U6, U3) of your device’s user guide.
  • Channel – The channel number of the particular IOType.

Outputs:

  • pValue – A pointer to the result value.