ESTUDIO DE IMPACTO AMBIENTAL PARA LA CONSTRUCCIÓN DE UN TERMINAL

Figure 3-1 illustrates the first part of the example. The figure shows an SNA host linked to a Tandem system (\SYS1). Residing on the host is the application TSO. Residing on \SYS1 are the TACL application, a Pathway application called Order Entry, a PATHMON process called $PATHX, and the Tandem Creator process. SCF is used to configure two gateway LUs (LU1 and LU2). These LUs enable LUNS to establish both static and nonstatic passthrough sessions for the two 3278 terminals (LU3 and LU4) attached to \SYS1.

Figure 3-1. Application Example, Part 1

010 Application: Application: Also: TSO ORDER ENTRY TACL CREATOR $PATHX SNAXUTL LU1 LU2 \SYS1 PU2 LU3 LU4 $P2 PU1 $G1 Host

Creating the Basic Configuration

Operational Assumptions The following are operational assumptions:

Only two terminals on \SYS1 will use LUNS. While other SNA terminals might be connected to \SYS1, they will remain unaffected by LUNS operation.

Both terminals will receive Tandem’s ESS message 10 (banner message) when they are started with SCF. When HELP is entered on a terminal, that terminal will receive a menu that has been created with the SNAXUTL ADD ESSMSG command.

Terminal LUs will initiate all sessions by means of character-coded commands. Therefore, for this example, they can log on to:

The TACL process on \SYS1 with the command TACL

The Order Entry process on \SYS1 with the command ORDERENTRY The TSO process on the host system with the command TSO

For the Order Entry application, LUNS will use the protocol assigned in the ESS table logon record named ORDERENTRY. For this example, the protocol is CRT. Because both terminals will be given the appropriate protocol (ITI) for the TACL application by means of the SCF ADD LU command, it is not necessary to specify a protocol for the TACL process. Because TSO is a host program accessed by means of passthrough, it is not necessary to specify a protocol in this case either. The ESS table will contain a record whose command-name field is the character- coded command “LOGOFF”. This command will allow the terminal user to log off from Order Entry and TSO (and the Inventory application when it is added in the second part of the example).

The TACL will be associated, through SCF, with the Tandem Creator process. Order Entry’s logon record will contain the subdevice name of the Tandem Creator process in its PLUNAME field. The logon records for both processes will contain a CONCDATA field specifying startup parameters. The Creator process uses these parameters when it creates the TACL and when it interfaces with the PATHMON $PATHX to log on LU3 and LU4 to Order Entry.

Terminals will receive all Tandem ESS messages. All host USS messages will be presented to a terminal when it is in session with TSO.

Terminal users will be able to establish a static passthrough path with the host system by entering the HOST command. They will thereby receive the host’s USS message 10. They can return to the Tandem system and receive ESS message 10 by entering the TANDEM command.

Creating the Basic Configuration

Configuration Assumptions The following are configuration assumptions:

The starter SET table provided by Tandem has been made active through

SYSGEN. SNAX/XF has thus already initialized the LUNS component of $SSCP. (Most users will prefer to build their own SET table and specify the SET table name through the SETTAB parameter of the SCF ADD/ALTER SUBSYS $SSCP command. The second part of the application example shows how to do this; see “Using SCF to ADD the New Application and LU to \SYS2.”)

Only one ESS table will be created. It will have the table name ESS1 and will not be flagged as the default table. SCF ADD APPL commands will define the TACL application, the Tandem Creator process, and SNAXUTL to LUNS, giving these processes subdevice names of #TACL, #CREATE, and #SNAXUTL, respectively. Note that the inclusion of an ADD APPL command for SNAXUTL allows for the dynamic modification of the ESS table. (In the second part of this application example, ESS1 will be modified dynamically; see “Updating the ESS Table on \SYS1.”)

TSO, and the Pathway application, Order Entry, need not be defined by an ADD APPL statement.

Because ESS1 is not a default table, it must be associated with each terminal individually. This is done through the ESSTABLE attribute of the SCF ADD LU command that defines each terminal LU. (Also see “Performance

Considerations—ESS Table Allocation” in this section.)

Gateway LUs (LU1 and LU2) will have the SCF attribute PASSTHRU ON, but not STATIC ON or ASSOCIATE.

Creating a Command File for SNAXUTL

In the following edit command file, SNAXUTL commands add: Logon and logoff records in the ESS table

A user message record (a HELP menu) in the ESS table A record in the SET table that identifies the ESS table

Note that the ESS table is created first. Because a new table is being created, the ALLOCATE command is used.

Creating the Basic Configuration

BEGIN

SELECTFILE $SYSTEM.SNAX.ESSTAB1, TYPE ESS ALLOCATE 10

ADD ESSCMD TACL, & CMDTYPE LOGON-CHAR, & PLUNAME #TACL, & CONCDATA "TACL, CPU 0"

ADD ESSCMD ORDERENTRY, & CMDTYPE LOGON-CHAR, & PROTOCOL CRT, & PLUNAME #CREATE, & CONCDATA ("PATHWAY NAME $PATHX,", & "PROGRAM ORDER-ENTRY")

ADD ESSCMD TSO, & CMDTYPE LOGON-INIT, & SENDHOST Y, & PLUNAME TSO, & GATELINE \SYS1.$G1

ADD ESSCMD LOGOFF, & CMDTYPE LOGOFF

ADD ESSCMD HOST, & CMDTYPE ORDER, & STATIC ON, & GATELINE \SYS1.$G1

ADD ESSCMD TANDEM, & CMDTYPE ORDER, & STATIC OFF

ADD ESSMSG HELP, & MSGTEXT (" ", & %H85," PU: @@NDNAME.@@LNNAME.@@PUNAME ", & %H85," LU: @@NDNAME.@@LNNAME.@@LUNAME ", & %H85," TO ACCESS ENTER ", & %H85," --- --- ", & %H85," TACL TACL ", & %H85," ORDER ENTRY ORDERENTRY ", & %H85," TSO TSO ", & %H85," HOST HOST ", & %H85," TANDEM TANDEM ", & %H85," ", & %H85," TO LOGOFF LOGOFF ")

Creating the Basic Configuration

The HELP menu includes “new line” control characters so that the display will be properly formatted. (For a discussion of New Line control characters, see the IBM 3270

Information Display System 3274 Control Unit Description and Programmer’s Guide.) Note

that New Line is the only control character accepted on the SSCP-LU session. Note also that the New Line control characters are coded in ASCII-hexadecimal format (%H85), rather than in EBCDIC-hexadecimal format (%H15). The characters must be ASCII-hexadecimal because the Tandem service manager translates the entire message from ASCII to EBCDIC automatically.

The HELP message also includes the keywords @@NDNAME, @@LNNAME, @@PUNAME, and@@LUNAME. Inclusion of these keywords in any part of an ESS message results in the display of the Tandem node name, the line name, the PU name, and the terminal LU name respectively. Thus, for LU3, the top portion of the HELP message would display the following:

PU: \SYS1.$P2.#PU2 LU: \SYS1.$P2.#LU3

Now that the commands that build the ESS table have been coded, a record for that ESS table must be added to the SET table. This record assigns a name to the ESS table and thereby identifies it to LUNS. It also specifies the name of the file where LUNS can access the table information.

BEGIN

SELECTFILE $SYSTEM.SYS01.SNXSET, TYPE SET

ADD SETESS ESS1, & FILENAME $SYSTEM.SNAX.ESSTAB1

END

It is assumed that the SET table referenced through the SELECTFILE command is the starter SET table source file; hence an ALLOCATE command is not included. It is also assumed that the SET table name was specified during stem generation. Thus, the referenced SET table source file resides on the volume and subvolume from which SNAX/XF was cold-loaded.

The second part of this application example shows you how to build your own SET table and specify its name through the SETTAB parameter of the ADD/ALTER SUBSYS $SSCP command.

Creating the Basic Configuration

Configuring the System Through SCF

In the previous subsection, SNAXUTL modified the SET table source file and SET table object file to include a record for ESS1. In configuring the system, the SETTAB

attribute of the SCF ALTER SUBSYS $SSCP command must be specified so that LUNS will use the modified version of the SET table and be aware of ESS1:

ALTER SUBSYS $SSCP,SETTAB $SYSTEM.SYS01.SNXSET

The ADD APPL command is used to assign subdevice names to the Tandem Creator process, the TACL application, and SNAXUTL on \SYS1. The TACL process (#TACL) is associated with the Tandem Creator process through the CREATOR attribute; the APPLFILE attribute is also specified so that the Creator process can locate the object file of the TACL.

ADD APPL $SSCP.#CREATE, APPLTYPE LUNSCRE, & PASSWORD "SYZYGY "

ADD APPL $SSCP.#TACL, APPLTYPE LUNSAPPL, & APPLFILE $SYSTEM.SYSTEM.TACL, & CREATOR #CREATE

ADD APPL $SSCP.#SNAXUTL, APPLTYPE LUNSAPPL, & PASSWORD "SNAXUTL "

Note that the Creator process is given the password “SYZYGY ” and SNAXUTL the password “SNAXUTL ”. Remember that the password must be right-filled with blank spaces, up to its total of eight characters.

Next, the gateway passthrough logical units are configured. The ADD LINE command is used to define the gateway line ($G1). Then the ADD PU command is used to define the gateway physical unit (PU1). Finally, the ADD LU command is used to define the two gateway LUs (LU1 and LU2):

ADD LINE $G1, STATION SECONDARY

ADD PU $G1.#PU1, TYPE (13,2),RECSIZE 265,MAXLUS 2, & MAXPTS 2, ADDRESS %HC1

ADD LU $G1.#LU1, TYPE (14,0),PUNAME #PU1,RECSIZE 1024, & PROTOCOL SNALU,PASSTHRU ON,ADDRESS 2

ADD LU $G1.#LU2, TYPE (14,0),PUNAME #PU1,RECSIZE 1024, & PROTOCOL SNALU,PASSTHRU ON,ADDRESS 3

Then the primary line ($P2) and its attached PU and LUs are configured. When the two terminal LUs (LU3 and LU4) are configured, PROTOCOL is specified as ITI. PROTOCOL is a required SCF attribute for any LU. Note, however, that this protocol specified through SCF can be overridden by the protocols specified in the ESS table logon records.

Creating the Basic Configuration

Note also that the ESS table is being specified as an attribute of each LU. This table, here identified by its table name, will be searched when LU3 or LU4 attempts to log on:

ADD LINE $P2, CHARACTERSET EBCDIC, STATION PRIMARY

ADD PU $P2.#PU2, TYPE (13,2),RECSIZE 265, & MAXLUS 2,ADDRESS %HC8

ADD LU $P2.#LU3, TYPE (14,2),PUNAME #PU2,RECSIZE 1024, & PROTOCOL ITI,ADDRESS 2,DEVTYPE "3278-2", & ESSTABLE ESS1

ADD LU $P2.#LU4, TYPE (14,2),PUNAME #PU2,RECSIZE 1024, & PROTOCOL ITI,ADDRESS 3,DEVTYPE "3278-2", & ESSTABLE ESS1

Note that CHARACTERSET EBCDIC is specified for the line; this turns translation on for the attached terminal LUs because they do not have CHARACTERSET specified as an LU attribute. Finally, the START command is used to start all lines, PUs, and LUs:

START LINE $G1 START PU $G1.#PU1 START LU $G1.#LU1 START LU $G1.#LU2 START LINE $P2 START PU $P2.#PU2 START LU $P2.#LU3 START LU $P2.#LU4

Note that before the host SSCP and TSO application can be accessed, the corresponding objects for LU3 and LU4 must also be started on the host side. Starting the Tandem

Creator Process

For Tandem applications to use LUNS services, the Creator process must be started. Because a password is required for the Creator process, it must be included as part of the RUN command.:

1> RUN CREATOR /OUT $S.#SPOOL, CPU 1, NAME $CRT, NOWAIT/ 2 ; & CREATOR #CREATE, PASSWORD "SYZYGY "

Note that this password was previously specified in the SCF ADD APPL command for the Creator process. The password in the RUN command must match the one

Adding an Application and Terminal to a Second System

Adding an Application