TCP/IP TELNET Management Programming Manual

Commands
Management Programming for the TELNET Subsystem
2–6 53474 Tandem Computers Incorporated
Event Messages An event message describes an event that has occurred in a subsystem, such as a
hardware error or a software error. All event messages are in SPI message format.
All event messages issued by the TELNET subsystem are sent to the EMS collector
process ($0). These event messages are then placed into the user-specified log files.
Once placed into the log files, the EMS consumer distributor process can read the
event messages and retrieve the selected events for the management application.
A management application retrieves event messages by sending commands in SPI
message format to an EMS consumer distributor.
To select event messages, you can write a filter that is specific to your needs. If no
filter is used, all event messages in the log file are passed to the management
application by the consumer distributor.
Figure 2-1 shows the flow of data between the TELNET subsystem and a management
application in the EMS environment. Note (in the figure) that event messages can also
be retrieved interactively through the VIEWPOINT console application. For further
details on the VIEWPOINT application, refer to the VIEWPOINT Manual.
For detailed descriptions of event messages and event management as they relate to
the TELNET subsystem, refer to Section 7, “Event Management.” For a description of
event messages and event management in general, refer to the Event Management
Service (EMS) Manual.
Communicating With
the TELNET
Subsystem
A management application communicates with the TELNET subsystem by means of
SCP or the EMS consumer distributor process. When communicating with SCP or
EMS, an application calls SPI procedures to build messages to be sent to the subsystem
and to retrieve messages sent from the subsystem. However, to send and receive SPI
messages and to establish and terminate communication with SCP or the EMS
distributor process, an application must use the GUARDIAN 90 file system.
How you use the GUARDIAN 90 file system depends on the language in which your
application is written. If your application is written in TAL or C, you must use the file-
system procedures directly (using functions or procedures) to send and receive the
SPI messages. If your application is written in COBOL85, you must use the file-system
procedures indirectly by invoking them through COBOL85 verbs. If your application
is written in TACL, you must use the file-system procedures indirectly by invoking
them through TACL built-ins.
Regardless of the language you are using, an application must perform the following
tasks when communicating with either SCP or the EMS distributor process:
1. Establish communication with SCP or the EMS distributor process.
2. Call SPI procedures to build a message.
3. Send the message to SCP or the EMS distributor process.
4. Receive the response.
5. Check for error codes and handle any errors.