When an MHP is to receive an MCF event, it uses the function for receiving ordinary messages (dc_mcf_receive()).

The MCF event is passed to the MHP for an MCF event as a logical message consisting of multiple segments. The first segment has MCF event information and the second and subsequent segments carry the segments of the unprocessed message. The first segment of the original message is on the second segment of the MCF event message and the n-th segment of the original message is on the (n + 1)-th segments of the MCF event message.

ERREVT2 or ERREVT3 is passed to the MHP for an MCF event that is started by the error event notification facility (when errevt=yes is specified in the -n option of the application attribute definition mcfaalcap) when a failure occurs in a communication event. MCF event information is set in the first segment and MCF event information about the communication event that failed is set in the second segment.

The figure below shows the segment layout of a logical message passed as an MCF event.

Figure 3-31 Segments of logical message passed as MCF event

MCF event information is reported according to the high-level language (C or COBOL) in which the MHP for an MCF event is written.

For MHPs written in C, MCF event information can be received with a structure. The structure is defined in the header file <dcmcf.h>. Include <dcmcf.h> with the #include statement for the MHP which handles MCF event information. For some communication events, the structure may be defined in the header file for each communication protocol supporting product.

For MHPs written in COBOL, MCF event information can be received with a segment list. Desired data can be fetched from any byte position of the segment.

The data format of MCF event information varies with the communication protocol supporting product (TP1/NET/xxxx). For details of the data format of the following MCF event information, see the applicable OpenTP1 Protocol manual:

• ERREVT1
• ERREVT2
• ERREVT3
• ERREVTA
• SERREVT
• SCMPEVT
• CERREVT (VERREVT)
• COPNEVT (VOPNEVT)
• CCLSEVT (VCLSEVT)

For details on the data format of ERREVT4 MCF event information, see the applicable OpenTP1 Programming Reference manual.