DFHMAH2 field definitions

The following definitions describe the content of each field in the CICS® Service Flow Runtime passthrough message header (DFHMAH2).

DFHMAH2-STRUCID
Structure Identifier. The value must be MAH2. This is always an input field. The initial value of this field is MAH2.
DFHMAH2-VERSION
Structure version number. The value must be +1 for CICS Service Flow Runtime processing. The field can have the following values:
  • +1 = CICS Service Flow Runtime structure version
This is always an input field. The initial value of this field for CICS Service Flow Runtime = +1.
DFHMAH2-STRUCLENGTH
Length of DFHMAH2 structure. The value must be +164. This is always an input field. The initial value of this field is +164.
DFHMAH2-RESERVED
Reserved.
DFHMAH2-FORMAT
CICS Service Flow Runtime request / reply name format name. This is the format name of the application message data that follows the DFHMAH2 structure. This is an input or output field. The initial value of this field is spaces. This is an input or output field. The initial value of this field is spaces.
DFHMAH2-DATALENGTH
This field indicates the length of the inbound application request or outbound application reply data following this header structure data inclusive of the CICS Service Flow Runtime passthrough header structures CIA-SCREEN-HEADER and CIA-MAP-HEADER.

This length does not include the lengths of any WebSphere® MQ header structures, the length of the DFHMAH header structure and the length of this DFHMAH2 header structure. It represents the fixed format length of the inbound application request data or outbound application reply data not including the length of any XML tags, and XML declaration data, if present.

For CICS Service Flow Runtime XML and non-XML passthrough requests, this field should indicate the total of the fixed format length of the CIA-SCREEN-HEADER structure (+36 bytes) plus the fixed format length of the CIA-MAP-HEADER structure (+102 bytes) plus the fixed format length of any application data structure (ADS), 3270 data-stream or unformatted application request data if present. This field should NOT indicate the length of the XML formatted request application data.

This field should NOT indicate the length of the XML formatted request application data on input. The field value may be larger than the actual length of the request data passed but should not be smaller than required or data truncation may occur causing unexpected results.

Note: For inbound XML requests that include tag data that is to be placed in an application data structure (ADS) for a subsequent RECEIVE MAP, the length to be used for the application data length used in the calculation above is the length of the ADS not the length of the inbound XML formatted application request data. The length of the ADS can be found in the field CIAMH-MAP-DATA-LENGTH within the CIA-MAP-HEADER structure when a SEND MAP vector is returned.

For information on how the CICS Service Flow Runtime processes an XML message header, see XML request and response processing

This field is input on requests and output on replies. For inbound request messages, this field determines the length of the input data container that holds the request application data. The initial value of this field is zero. The request data length is determined by the service requestor. The reply data length is set by the CICS Service Flow Runtime.

DFHMAH2-TRANSID
This field indicates the target application transaction ID to run. It is an optional field but must be provided on the initial application request. This is an input field.
DFHMAH2-RECEIVE-TYPE
This field indicates the inbound vector type that the runtime must build and use to satisfy the previous outbound vector type sent from the target CICS application. The value is one of the following:
  • 0 = No RECEIVE
  • +1 = RECEIVE MAP vector
  • +2 = RECEIVE vector
This is an input field. The initial value of this field is zero.

A RECEIVE vector (+2) should be used when initiating user transactions with unformatted input data via the Link3270 bridge mechanism. See CIA-MAP-HEADER field definitions for further information.

DFHMAH2-NEXT-TRANSID
This field indicates the next target CICS application transaction ID to run as indicated by the target CICS application. This is an output field. The initial value of this field is blanks.
DFHMAH2-USE-FKEEPTIME-IND
This field indicates if the value in DFHMAH2-FACILITYKEEPTIME should be used as the bridge facility maximum keeptime. The value is one of the following:
  • Zero = Do not use DFHMAH2-FACILITYKEEPTIME
  • +1 = Use
This is an input field. The initial value of this field is zero.

For information on FACILITYKEEPTIME, see the CICS External Interfaces Guide.

DFHMAH2-FACILITYKEEPTIME
This field defines the maximum length of time the bridge facility will be kept if inactive (i.e., keeptime).

Bridge facilities are deleted automatically if they are inactive for the keeptime interval. This field value is used to load the bridge header (BRIH) field BRIH-FACILITYKEEPTIME. If the bridge facility is not explicitly deleted, it is scheduled for deletion automatically by CICS if it is unused for the time specified in the BRIH-FACILITYKEEPTIME field, or in the BRMAXKEEPTIME system initialization parameter. The smaller interval is used. If a value is not provided for this field, a default value of 300 seconds is used unless overridden by BRMAXKEEPTIME.

This is an input field. The initial value of this field is zero.

DFHMAH2-FACILITYLIKE
This field defines the FACILITYLIKE value to be used on a bridge facility allocate request. The value is the name of a real terminal resource definition that is used as a template for some of the properties of the bridge facility. With the Link3270 bridge mechanism, you do not provide a TERMINAL resource definition for the bridge facility, but you can control the terminal properties used by providing a 3270 TERMINAL resource definition to be used as a template. This TERMINAL definition is known as the FACILITYLIKE. This field value is used to load the bridge header (BRIH) field BRIH-FACILITYLIKE on the allocate facility request. If the facility is reused, this value is ignored on subsequent calls to the bridge mechanism.

This is an input field. The initial value of this field is spaces. For information on FACILITYLIKE, see CICS External Interfaces Guide

DFHMAH2-GETWAITINTERVAL
This field defines the maximum wait interval for message input (in milliseconds). This field value is used to load the bridge header (BRIH) field BRIH-GETWAITINTERVAL on bridge requests. The actual value used is the smaller of the BRIH-GETWAITINTERVAL and the RTIMEOUT value for the target CICS transaction.

This is an input field. The initial value of this field is zero.

DFHMAH2-VECTOR-LOGGING
This field indicates whether vector logging is enabled and if so the type of logging to be performed. Valid values for this field are as follows:
  • Zero = no vector logging
  • +1 = full vector logging (vector headers (BRIH/BRIV) and vector data)
    Note: When using full vector logging (MP-BR-VECTOR-LOGGING = +1; see Link3270 node properties) the vector data that will display as contents in the vector dump is the accumulated map buffer or text data that is returned to the generated Link3270 navigator. The buffer contents in the vector dump may not always contain the individual vector data returned from the Link3270 bridge mechanism.
  • +2 = trace logging (vector headers (BRIH/BRIV) only)

This is an input field. The initial value of this field is zero.

DFHMAH2-DEALLOCATE-IND
This field indicates when to deallocate a Link3270 facility and delete any associated session state data. Valid values for this field are as follows:
  • Zero = don't deallocate
  • +1 = deallocate
  • +2 = deallocate if processing is successful
  • +3 = deallocate if processing is unsuccessful

This is an input field. The initial value of this field is zero.

DFHMAH2-SEND-AID-FIRST
This field indicates if an initial AID byte is to be sent to satisfy a RECEIVE/RECEIVE MAP vector or to clear a pseudo-screen before processing additional inbound vectors. The AID byte to send is found in field DFHMAH2-INITIAL-AID-BYTE. Valid values for this field are as follows:
  • Zero = do not send an initial AID byte
  • +1 = send an initial AID

This is an input field.

DFHMAH2-INITIAL-AID-BYTE
This field indicates the initial AID byte (pseudo-function key) to be sent to satisfy a RECEIVE/RECEIVE MAP/CONVERSE vector or to clear a pseudo-screen of data if DFHMAH-SEND-AID-FIRST indicates to do so. Valid values for this field can be found in the DFHAID CICS copybook.

This is an input field. The initial value of this field is spaces.

DFHMAH2-CLIENTIP-ADDRESS
This field defines the client IP. Use is optional. May be used to identify a workstation or DHCP hub which may then map to a local CICS owned printer. Many CICS applications map a physical terminal to a physical printer. For example, several terminals may all be mapped to the same printer in an office location. This field is intended to provide similar support for a Web interface to CICS applications. If the Java™ client can provide the client IP address then it may be possible to map the address to a CICS owned printer. This is an input field. The initial value of this field is spaces.
Note: This field is not currently implemented.
DFHMAH2-RESPTIME
This field indicates the CICS Service Flow Runtime response time in milliseconds. Application response time is included in this response time value.

This is an output field. The initial value of this field is zero.

DFHMAH2-APPLRESPTIME
This field indicates the CICS target application response time in milliseconds.

This is an output field. The initial value of this field is zero.

DFHMAH2-XML-PROGRAMID
This field indicates, if the request and reply are in XML format, the name of the XML parse program to call for application data request/reply portion of the CICS Service Flow Runtime message structure. If the elementary item, DFHMAH-XML-PROGRAM-TAG, is left blank, a call to program name = DFHMAH-XML-PROGRAM + "I" will be made to parse XML application request data during request processing and a call to program name = DFHMAH-XML-PROGRAM + "O" will be made to generate XML application reply data during reply processing. If the DFHMAH-XML-PROGRAM-TAG is not equal to spaces, the program called will be the same to parse XML application request data on input and to build XML application reply data on output. This is an input field. The initial value of this field is spaces. See XML request and response processing
Note: This field is not currently implemented.
DFHMAH2-RESERVED2
Reserved.