DFHMAH2 header structure

The request message header DFHMAH2 describes the structure of the application data for a passthrough request message. It is mapped by copybook DFHMAH2V, which is located in the library SCIZMAC.

When the DFHMAH-UOWCONTROL field in DFHMAH has a value of 3, the DFHMAH2 header structure is required. The DFHMAH-FORMAT field in DFHMAH must also have a value of MAH2 to indicate the existence of the DFHMAH2 header structure in the inbound passthrough request.

Note: The associated headers CIA-SCREEN-HEADER and CIA-MAP-HEADER are mapped by copybooks DFHMALSH and DFHMALMH respectively. These copybooks are also located in the library SCIZMAC.

The following table highlights field information within the DFHMAH2 message header structure.

A field's type can be one of the following:
  • X - the field contains characters.
  • 9 - the field is a numeric.
  • FB - the field is a fullword binary.
Table 1. DFHMAH2 passthrough message header fields
Disp. Length Type Field Req Values
0 04 x DFHMAH2-STRUCID Y MAH2
4 04 FB DFHMAH2-VERSION Y +1
8 04 FB DFHMAH2-STRUCLENGTH Y +164
12 08 x DFHMAH2-RESERVED N  
20 08 x DFHMAH2-FORMAT N  
28 04 FB DFHMAH2-DATALENGTH Y  
32 04 x DFHMAH2-TRANSID N  
36 04 FB DFHMAH2-RECEIVE-TYPE Y zero, +1, +2
40 04 x DFHMAH2-NEXT-TRANSID N  
44 04 FB DFHMAH2-USE-FKEEPTIME-IND N
48 04 FB DFHMAH2-FACILITYKEEPTIME N
52 04 x DFHMAH2-FACILITYLIKE N  
56 04 FB DFHMAH2-GETWAITINTERVAL N  
60 04 FB DFHMAH2-VECTOR-LOGGING N zero, +1, +2
64 04 FB DFHMAH2-DEALLOCATE-IND N zero, +1, +2, +3
68 04 FB DFHMAH2-SEND-AID-FIRST N zero, +1
72 01 x DFHMAH2-INITIAL-AID-BYTE N  
73 39 x DFHMAH2-CLIENTIP-ADDRESS N  
112 04 FB DFHMAH2-RESPTIME N  
116 04 FB DFHMAH2-APPLRESPTIME N  
120 08 x DFHMAH2-XML-PROGRAMID N  
128 36 x DFHMAH2-RESERVED2 N