Local system definitions
When you define an MSC network, you need to define transactions, logical terminals, and physical and logical connections in each local system. You can define these resources by using system definition macros, or you can define them dynamically by using IMS type-2 CREATE commands for the resource type you are defining.
More specifically, for each local system you need to define:
- All transactions entered or processed by that system
- All logical terminals that are attached to that system and all logical terminals in remote systems that are referenced by transactions processed in that system, or by terminal operators, unless either a Program Routing exit routine is used or MSC directed routing is used
- The physical and logical connections between that system and the remote systems that share in the processing of the specified transactions
The system definition macros that you need to prepare in each system are summarized in the following table. The first macro that you use is IMSCTRL. Using the MSVID keyword, you assign a number in the range from 1 to 255 as a unique identifier of that system. This causes a control block, DFSMSxxx, to be built for use with the Multiple Systems Verification utility. (The 3-digit suffix, xxx, matches the MSVID parameter; one unique control block exists for each system in the MSC network.) This offline utility helps verify that system definitions for all partner systems are consistent. The IMSMSV procedure is generated in IMS.SDFSPROC in order to execute this utility.
| Resource | Identification | Macro | Number coded |
|---|---|---|---|
| System | System ID | IMSCTRL | 1 |
| Programs | PSB name | APPLCTN | 1 per PSB |
| Local transactions | Transaction code | TRANSACT | 1 or more per APPLCTN |
| Remote transactions | Transaction code | TRANSACT | 1 or more per APPLCTN in a remote system |
| Physical connections | Physical link name | MSPLINK | 1 per connection |
| Logical connections | Logical link name | MSLINK | 1 or more per MSPLINK, depending on the physical link type1 |
| Routing names | Logical path name | MSNAME | 1 or more per MSLINK |
| Local terminals | LTERM name | NAME | 1 per local terminal |
| Remote terminals | LTERM name | NAME2 | 1 per remote terminal |
- Multiple-session TCP/IP physical links and VTAM® physical links have additional MSLINK macros. Channel-to-channel (CTC) and memory-to-memory (MTM) physical link types can have only one logical link per physical link.
- Define with an ETO MSC descriptor if the corresponding local terminal is an ETO terminal.