National Instruments NI-488.2 Benutzerhandbuch

© National Instruments Corporation

This chapter describes several ways to debug your application.

The NI Spy utility monitors NI-488.2 API calls made by NI-488.2 
applications. If an application does not have built-in error detection 
handling, you can use NI Spy to determine which NI-488.2 call is failing.

For more information about using NI Spy, select Help»Help Topics 
in NI Spy or refer to Chapter 6, 

At the end of each NI-488.2 call, the global status variables (

ibsta

, 

iberr

, 

ibcnt

, and 

ibcntl

) are updated. If you are developing an 

NI-488.2 application, you should check for errors after each NI-488.2 call. 
If a NI-488.2 call failed, the high bit of 

ibsta

 (the 

ERR

 bit) is set. For a 

failed NI-488.2 call, 

iberr

 contains a value that defines the error. In some 

error cases, the value in 

ibcntl

 contains even more error information.

Once you know which NI-488.2 call fails, refer to Appendix B, 

, and Appendix C, 

, for help 

understanding why the NI-488.2 call failed. This information is also 
available in the NI-488.2 online help. For instructions on accessing the 
online help, refer to the 

 section in 

The error variable, 

iberr

, is meaningful only when the ERR bit in the 

status variable, 

ibsta

, is set. For a detailed description of each error and 

possible solutions, refer to Appendix C,