IMS Transaction Manager services
This topic describes several specialized optional Transaction Manager services.
APPC/IMS and LU 6.2 devices
APPC/IMS is a part of IMS TM that allows you to use Common Programming Interface Communications (CPI-C) to build CPI application programs. APPC/IMS supports APPC with facilities provided by APPC/MVS.
- Be started from an APPC LU 6.2 device
- Receive input messages from originating LU 6.2 devices
- Send output messages back to originating LU 6.2 devices
- Start transaction programs on remote LU 6.2 devices
The same application program can work with all device types (LU 6.2 and non-LU 6.2) without new or changed coding.
The explicit application programming interface (API) for APPC support is the CPI-C interface, and it is available to any IMS application program. The IMS application program can issue calls 1 to APPC/MVS through this interface.
Fast Path
Fast Path is capable of performing transaction and database processing at high rates. When your system requirements include a high transaction volume, using Fast Path can be advantageous if you do not require all the facilities of full-function processing. Examples of such applications include teller transactions in banking and point-of-sale transactions (inventory update) in retail marketing. Fast Path input and output messages use the expedited message handler (EMH) and bypass message queuing and the priority-scheduling process.
Extended Terminal Option (ETO)
IMS Extended Terminal Option (ETO) provides dynamic terminal and local and remote logical terminal (LTERM) support for IMS TM.
Definition: A logical terminal (LTERM) is a user destination. For statically defined terminals, each LTERM is associated with a physical terminal. For ETO terminals, each LTERM is associated with a user, and is associated with a physical terminal only after a user has signed on to a physical terminal.
You can add terminal hardware and LTERMs (users) to the IMS without first defining them. ETO gives you the option of eliminating macro statements in the IMS system definition of VTAM® terminals and LTERMs. ETO enhances the availability of your IMS by eliminating the need for you to bring the system down in order to add terminals and LTERMs.
ETO also enhances security for the IMS TM user by associating all output with a specific user, instead of with a device. ETO requires the user to sign on.
ETO reduces the IMS system definition time for those systems where the terminal network is defined dynamically.
Intersystem Communication (ISC)
You can exchange data between your IMS and other external subsystems.
- Customer Information Control System (CICS®)
- Other IMS systems
- User-written subsystems
The session that is created between IMS and an external subsystem is called an application-to-application session. The IMS that operates in this session uses a function called Intersystem Communication (ISC), which uses SNA protocols.
Message Format Service (MFS)
IMS Message Format Service (MFS) is a facility that formats messages to and from terminals, so that application programs need not deal with device-dependent data in input or output messages. An application program can format messages for different device types using a single set of editing logic, even when device input and output differ from device to device.
IMS MFS formats messages to and from user-written programs in remote controllers and subsystems so that application programs need not deal with the transmission-specific characteristics of the remote controller.
Multiple Systems Coupling (MSC)
Multiple Systems Coupling (MSC) enables you to enter transactions in one IMS and process them in another IMS. The responses from IMS can be returned to the terminals that entered the transactions, or to other terminals.