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Generation properties of the LINK with Channel invoke type

This topic describes the generation properties of the LINK with Channel invoke type.

This topic contains the following subtopics:

General information

Important: The LINK with Channel invoke type is available only when the target runtime environment set in the generation properties file is CICS Service Flow Runtime: Level 2.0 (see CICS® Service Flow Runtime Levels 1.0 and 2.0).
Important: A LINK with Channel invoke node can validly occur only within a Nonterminal flow node (see About flow types).

The LINK with Channel invoke type causes the specified nonterminal application to be invoked by means of a CICS LINK command with the Channel option, as in the command line EXEC CICS LINK PROGRAM('payr') CHANNEL(payroll).

Channels and containers provide an easy and flexible mechanism for exchanging large volumes of structured parameter data between CICS programs

A channel is a uniquely named reference to a collection of application parameter data held in containers (see the definition of container in the next paragraph). Like a COMMAREA, a channel is used to transfer information between two programs within a transaction or to transfer information between two transactions from the same terminal. However, unlike a COMMAREA, a channel is not limited to a maximum size of 32KB.

A container is a named reference to a CICS-managed storage area that can hold any form of application data. A container may be any size and can hold data in any format that the application requires.

Note: The CICS Service Flow Runtime has a limitation of 999 input containers and 999 output containers per channel invocation of an application.

The CICS EXEC API command associates a named channel with a collection of one or more containers. This is an easy way of grouping parameter data structures that can be passed to a called application.

Compare the capabilities the LINK with Channel invoke type with those of the LINK with COMMAREA invoke type (see Generation properties of the LINK with COMMAREA invoke type).

Generation properties

For more information about these generation properties see the CICS Service Flow Runtime User's Guide (see Supported runtime environments for each project type).

Table 1. Generation properties of the LINK with Channel invoke type
NAME DESCRIPTION VALUE RANGE DEFAULT VALUE
Invoke Type Type of node used in the COBOL-based flow
  • LINK with COMMAREA
  • LINK with Channel
  • WebSphere® MQ
LINK with Channel
Activity Name Name of the activity performed by the node.
Note: When the runtime code is generated for the CICS Service Flow Runtime environment, the runtime code generator uses the information in this node to create a CICS Business Transaction Services (BTS) activity. The name that you specify here is used as the name of the new BTS activity.
String value: 1-32 characters Node ID
Comment Optional text associated with the node N/A N/A
Adapter name The CICS Service Flow Runtime uses this name to uniquely identify the Link with Channel invocation. String value: 1-8 characters A prefix of AD followed by the first 6 characters of the Invoke name.
Adapter Transaction ID The CICS TransID for the COBOL program that implements the LINK with Channel command. String value: 1-4 characters CMAS

You can override the default transaction ID by typing another transaction ID into this field.

An error message is displayed if the input field is blank or if the transaction ID begins with C and is something other than CMAS. (Transaction IDs beginning with C are reserved by CICS).

Link To Program Name Server side program to which a LINK with Channel invocation links. String value: 1-8 characters. Cannot be blank. LINK with Channel invoke program name
System ID Name of the CICS system where your user transactions (target CICS application transactions) are running String Blank
Link To Transaction ID Server side Transaction ID parameter (TRANSID) to specify on the LINK with Channel command N/A Blank
Syncpoint On Return Select to include the SYNCONRETURN parameter (indicating if the server region named in Sysid is to take a syncpoint on successful completion of the program) on the LINK command. N/A Not selected
Channel Name The name of the channel being passed on the LINK command. String value: 1-16 characters Blank
Application Input Containers Use this list to specify the input structures that you want to pass on the LINK command. Each output structure in the list will be treated as a container.

Container name: The name of the container. You must specify a value here.

Message: A data structure within the container. You cannot edit this field.

The following container names are restricted:
  • ADAPTER.PROCESS
  • ADAPTER.ERROR
  • COMMAND.STATUS
  • COMMAND.INPUT
  • COMMAND.OUTPUT
  • DPL.DATA
N/A
Application Output Containers Use this list to specify the output structures that you want to pass on the LINK command. Each output structure in the list will be treated as a container.

Container name: The name of the container. You must specify a value here.

Message: A data structure within the container. You cannot edit this field.

Optional: (a) A value of true signifies that the invoked application need not return the container. (b) A value of false signifies that the invoked application must return the container.

The following container names are restricted:
  • ADAPTER.PROCESS
  • ADAPTER.ERROR
  • COMMAND.STATUS
  • COMMAND.INPUT
  • COMMAND.OUTPUT
  • DPL.DATA
N/A


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