Start the scanner interface trace with the MODIFY TRACE command or the TRACE start option. The COUNT option allows you to choose how many bytes of data you want traced (0 to 254 or ALL). The default is the entire PIU.

For more information on the MODIFY command for the scanner interface trace, see z/OS Communications Server: SNA Operation. For more information on the TRACE start option, see z/OS Communications Server: SNA Resource Definition Reference.

Make sure that the GTF with the TRACE=USR option is active before starting this trace. Use ACF/TAP with INPUT=LINE to format and print the output.

For more information on printing trace output, see Formatting and printing trace records.