VTAM Exit Services message parameter list

The VTAM® Exit Services parameter list contains a pointer to an input parameter list which is provided by the exit calling VTAM Exit Services. For the message function, the input parameter list is the VTAM Exit Services Message parameter list (EXMPL). The format of the VTAM Exit Services Message parameter list is in Table 1.

Note: Each time VTAM calls the session management exit routine, the VTAM Exit Services parameter list is initialized. This results in the pointer to the EXMPL being zeroed. The exit must always update the VTAM Exit Services Message parameter list pointer before calling VTAM Exit Services.

Table 1. VTAM Exit Services message parameter list
Dec (Hex) Offset	Size (Bytes)	Value when Calling VTAM Exit Services	Description
0 (0)	2	N/A	Reserved
2 (2)	2	Set by session management exit	A 16-bit signed number which represents the length of the message text. This number must be greater than 0 and less than or equal to 4096 (decimal). The maximum supported length is 4096 (decimal) bytes per invocation of VTAM Exit Services.
4 (4)	4	Set by session management exit	The address of the message text to be issued by VTAM Exit Services on behalf of the session management exit.

For information about design considerations and examples of invoking VTAM Exit Services, see VTAM exit services.