•
When the line between the Gateway-ST and IBM can be activated but the
PU (Gateway-ST) cannot be activated. Request a trace of all messages that
reach the Gateway-ST through VTAM buffers.
•
When the circuit from the Gateway-ST to IBM is active but you are not
sure whether you are communicating with the IBM host. Request a trace
of all messages that reach the Gateway-ST LUs through VTAM.
3.2.1.4 VTAM Line Trace
A line trace (TYPE=LINE), a joint function of VTAM and the IBM NCP, records
the status of a line each time the NCP receives data from or sends data to that
line. A line trace provides you with a record of the sequence of messages that
travel over a specific line between the Gateway-ST and ACF/NCP in the 37xx
communications controller. Request a line trace in the following situations:
•
When you suspect a problem with a device attached to the IBM 37xx
communications controller.
•
When you receive the error message ‘‘Circuit is not active.’’ This message
indicates that you cannot activate the line between the Gateway-ST and
IBM.
•
When the line to IBM from the Gateway-ST does not activate.
Note
Before using a line trace, you should use a generalized PIU trace
to verify whether the problem is in VTAM or with the application
program. Expect a very extensive trace listing when you ask for a
VTAM line trace. Do not ask for a VTAM line trace unless you are
trying to solve a line-related problem.
3.2.1.5 SDAID Trace Program
You can use the following SDAID traces to trace VSE events,
•
VTAMBU (VTAM buffer) trace provides a record of events when VTAM
uses a buffer in its buffer pool.
•
VTAMIO traces SVCs, SIO or SIOF instructions, and I/O interrupts.
For information about using the SDAID trace program, refer to the IBM
Virtual Storage Extended Advanced Functions: Service Aids, Version 2,
Release 2.
3–4 Traces
