Microsoft SNA Server provides several diagnostic mechanisms to use in 3270 emulator client application development. SNA Server provides one message file that you can use for error and audit logging. Your application can write error and audit log messages to SNA Server log files. SNA Server has one message file that is used for all its error and audit logging. In addition, SNA Server provides internal tracing macros that can be used to check the operation of the application during development. The COM_TRC_HLLAPI macro can be used within an HLLAPI library to trace the parameters supplied to an HLLAPI function as well as the returned values. Finally, SNA Server supports the facility for tracing message flows at the Function Management Interface (FMI), both at the local node and at the application's DL-BASE.
For detailed information about SNA Server diagnostic techniques and capabilities, see the Microsoft SNA Server documentation in the "Internet, Networking, and Distributed Services" section of the Microsoft Platform SDK.