User manual

Computer Gateway User Manual 2-11 5/96
2.4.2
2.4.2 Starting of CG-Host Processor Communications
Responsibility for establishing communication between the host processor and CG is left to
the CG. Whenever the CG is freshly loaded it attempts to make a Cold Restart. If
communications with the host processor are interrupted following a successful Cold
Restart, the CG then attempts a Warm Restart.
If communication is broken at any time, the failure should be recorded at the host-processor
operator terminal. The CG waits for three minutes before trying again. Some failures may
require reload of the CG.
2.4.3 Restart Modes
Once the Restart message is received, the host processor is expected to take the initiative for
completion of the startup. The necessary steps depend on the type of Restart.
A Cold Restart requires the host processor to prepare and download necessary elements of
the CG-resident database, such as ACP-to-ACIDP connections and any Internal Data
Tables. This also requires the completion of the host processor's own database, by the
preparation of its ACIDP/ACP status table, and the execution of any necessary external to
internal point-address conversions.
A Warm Restart requires the host processor to resolve any mismatch of databases between
the CG and host processor.
Upon completion of any restart, the host processor should display a restart message and the
CG can begin scheduling of ACPs.
Details of the required startup messages are found starting at paragraph 4.3. Also see Table
4-2 and Figure 4-1.
2.4.4 Initial Startup Recommendations
It is recommended that any system being brought up for the first time be configured for
Real-Time Journals to be kept by the History Module and to include System Error and
Maintenance Recommendations Messages. See paragraph E.3.1 for some first-time
scheduling recommendations.