If the EPI or the Client terminal emulator is to be used, the Client virtual terminals must be installed on CICS® on System/390®. Client virtual terminals are defined to CICS on System/390 as remote 3270 terminals.
Note the following:
You can use CEDA DEFINE and INSTALL commands to create static definitions of Client terminals. When you use static definitions:
Figure 30 and Figure 31 are example TERMINAL and TYPETERM definitions for Client terminals.
Note that:
Note that the terminal names passed by Clients are case-sensitive. That is, if a Client passes a name that contains lowercase letters, CICS does not translate it into uppercase. CICS searches for a remote terminal definition whose TERMINAL name is the same combination of mixed or lowercase letters.
DEFINE TERMINAL(VT12) GROUP(CLEPIVT) OVERTYPE TO MODIFY CEDA DEFine TErminal ==> VT12 Group ==> CLEPIVT AUTINSTModel ==> No No|Yes|Only AUTINSTName ==> TERMINAL IDENTIFIERS TYpeterm ==> CLIVT NEtname ==> CONSOle ==> No No|0-99 REMOTESystem ==> CLIA REMOTESYsnet ==> REMOTEName ==> ASSOCIATED PRINTERS PRINTERCopy ==> No No|Yes ALTPRINTCopy ==> No No|Yes PIPELINE PROPERTIES TAsklimit ==> No No|1-32767 OPERATOR DEFAULTS OPERPID ==> OPERPriority ==> 000 0-255 OPERRsl ==> 0 0-24,... OPERSecurity ==> 1 1-64,... PRESET SECURITY Userid ==> TERMINAL USAGES TErmpriority ==> 000 0-255 Inservice ==> Yes Yes|No SESSION SECURITY ATtachsec ==> Local Local|Identify|Verify| Persistent|Mixidpe BINDPassword ==> PASSWORD NOT SPECIFIED BINDSecurity ==> No No|Yes
Here is an example TYPETERM definition to accompany the preceding TERMINAL definition. It is based on the CICS-supplied TYPETERM, DFHLU2.
DEFINE TYPETERM(CLIVT) GROUP(CLEPIVT) OVERTYPE TO MODIFY CEDA DEFINE TYpeterm ==> CLIVT Group ==> CLEPIVT RESOURCE TYPE DEVice ==> LUTYPE2 TERmmodel ==> 2 SESsiontype ==> LDclist ==> SHippable ==> Yes No|Yes MAPPING PROPERTIES PAGesize ==> 024 , 080 0-999 ALTPage ==> 000 , 000 0-999 ALTSUffix ==> FMhparm ==> No No|Yes OBOperid ==> No No|Yes PAGING PROPERTIES AUTOPage ==> No No|Yes DEVICE PROPERTIES DEFscreen ==> 024 , 080 0-999 AUDiblealarm ==> Yes No|Yes EXtendedds ==> Yes No|Yes Query ==> All No|Cold|All SOsi ==> No No|Yes BAcktrans ==> No No|Yes CGcsgid ==> 00000 , 00037 0-65535 SESSION PROPERTIES AScii ==> No No|7|8 SENdsize ==> 01536 0-30720 RECEivesize ==> 00256 0-30720 BRacket ==> Yes Yes|No LOGMode ==> DIAGNOSTIC DISPLAY ERRLastline ==> Yes No|Yes ERRIntensify ==> Yes No|Yes ERRColor ==> No No|Blue|Red|Pink|Green| Turquoise|Yellow|NEutral ERRHilight ==> No No|Blink|Reverse|Underline OPERATIONAL PROPERTIES AUTOConnect ==> No No|Yes|All ATi ==> Yes No|Yes CReatesess ==> No No|Yes RELreq ==> Yes No|Yes DIscreq ==> Yes Yes|No MESSAGE RECEIVING PROPERTIES ROutedmsgs ==> All All|None|Specific LOGOnmsg ==> Yes No|Yes APPLICATION FEATURES BUildchain ==> Yes No|Yes USerarealen ==> 000 0-255 Ioarealen ==> 00256 , 04000 0-32767 UCtran ==> Yes No|Yes|Tranid
The preferred method of defining Client terminals is to use autoinstall, because it is more convenient when many terminals connect to a single server.
If you use autoinstall, you may need to create some model terminal definitions (that is, TERMINAL-TYPETERM pairs) for use with Client terminals, unless you have some existing ones that are suitable. The CICS-supplied autoinstall model DFHLU2 may be appropriate (it is the default if the Client does not specify a model name). Value 2 of the CGCSGID option of the TYPETERM definitions should specify the code page to be used by the CICS on System/390 server for data conversion.
The autoinstall model used to install a virtual terminal is determined using the following sequence:
For the Client terminal emulator:
From the /m (Modelname) parameter of the cicsterm command
used
to start the emulator, if specified by the workstation user.
The autoinstall user program cannot choose a different autoinstall model.
The terminal identifier (TERMID) passed to the CICS autoinstall function at install of a virtual terminal is determined using the following sequence:
For the Client terminal emulator:
From
the /n parameter of the cicsterm command
used
to start the emulator, if specified by the workstation user.
Note that the terminal names passed by Clients are case-sensitive--that is, if they contain lowercase letters, these are not translated into uppercase by CICS.
You can use the VTPREFIX system initialization parameter to override the default prefix assigned to CICS-generated TERMIDs. Use VTPREFIX to specify a different prefix, reserved for virtual terminals, on each TOR on which Client virtual terminals are to be installed. This ensures that the TERMIDs of Client terminals autoinstalled on each system are unique in your transaction routing network. This in turn prevents the conflicts that could occur if two or more terminal-owning regions ship definitions of Client virtual terminals to the same application-owning region.
If such a naming conflict does occur--that is, if a Client virtual terminal is shipped to an AOR on which a remote terminal of the same name is already installed--the autoinstall user program is invoked in the AOR. Your user program can resolve the conflict by allocating an alias terminal identifier to the shipped definition. (For details of writing an autoinstall user program to install shipped definitions, see your CICS on System/390 Customization Guide.)
If your server programs do make this assumption, you can use your autoinstall user program to allocate alias TERMIDs, by which the virtual terminals will be known to CICS, in a consistent manner. For further details, see Writing EPI server programs.
For definitive information about the VTPREFIX system initialization parameter, see your CICS on System/390 System Definition Guide.
The autoinstall user program:
For brevity, the TERMID specified by the Client or the CICS-generated "VTPREFIX" name is referred to as the supplied name. The Client always knows the virtual terminal by the supplied name. However, your autoinstall user program can allocate an alias, by which the virtual terminal will be known to CICS.
One reason for using your autoinstall program to assign aliases to Client terminals might be to ensure that particular identifiers relate consistently to particular Client terminals. Whether this consistency is required depends on how your server applications are coded--see Writing EPI server programs.
Your autoinstall user program cannot change the autoinstall model.
For further information about writing a user program to control the installation of Client virtual terminals, see your CICS on System/390 Customization Guide.
When an EPI program issues a CICS_EpiAddTerminal call, or the workstation user uses the cicsterm command to start an emulator session, the Client invokes the CTIN transaction to install or reserve the terminal definition on CICS on System/390.
Table 43 relates the parameters passed by the Client to the way in which CICS installs the Client terminal.
CICS_EpiAddTerminal parameters or cicsterm specified | CICS actions | ||||
---|---|---|---|---|---|
NetName | DevType or Model-
name |
Static definition exists? | Result | TERMID | Autoinstall model |
Yes | No | Yes | Use static definition 10 | Client- specified | - |
Yes | No | No | Call fails | - | - |
Yes | Yes | No | Autoinstall | Client- supplied 11 | Client- specified |
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No | No | - | Autoinstall | CICS- supplied 11 | DFHLU2 |
No | Yes | - | Autoinstall | CICS- supplied 11 | Client- specified |