Problem Determination Facilities - IBM 3274 User Manual

3. The communication facility level. Although some tests
may be initiated from the control unit or the host system,
problem determination at this level should be coordinated
at the host system.
4. The host system level, which may have problem
determination facilities that are available to all lower
levels. These are briefly described below, with a reference
to the appropriate publication for further details.
To expedite problem determination, when a problem is detected
at one level of the system, the problem should be reported to
the coordinator at the next higher level. To minimize the
impact on the system, problem determination should be done at
the lowest level.
Problem Determination Facilities
Each level of the system has associated problem determination
facilities that are used to isolate failures within the system.
Some of these facilities are used concurrently with the
I
operation of other system elements at that level and require
only the dedicated device being tested. An example of these
facilities is the concurrent test contained in the 3274 Control
Unit, which is used to test the features of attached display
stations and printers. Other facilities are used offline and
require dedicated use of all the system elements affected. An
example of these facilities is the basic assurance tests
contained in the 3274 Control Unit.
The network problem determination facilities that may be
available at the host system are the following:
• Display Exception Monitoring Facility (DEMF)
• Facility Error Recognition System (FERS)
• Network Problem Determination Application (NPDA).
These facilities are described in the appropriate manuals listed
under "Related Publications," on page iv of this guide.
Section 2. Problem Determination
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