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Status-Acknowledge(Nack-2)

  • Article

The Status-Acknowledge(Nack-2) message flows from the node to the application. It is used with both system services control point (SSCP) and primary logical unit (PLU) connections.

Syntax

  
struct Status-Acknowledge(Nack-2) {  
    PTRBFHDR  nxtqptr;  
    PTRBFELT  hdreptr;  
    CHAR      numelts;  
    CHAR      msgtype;  
    CHAR      srcl;  
    CHAR      srcp;  
    INTEGER   srci;  
    CHAR      destl;  
    CHAR      destp;  
    INTEGER   desti;  
    CHAR      sfhdr.stackhdr.akstat;  
    CHAR      sfhdr.stackhdr.akqual;  
    INTEGER   sfhdr.stackhdr.akmsgkey;  
    CHAR      sfhdr.stackhdr.akflags1;  
    CHAR sfhdr.stackhdr.akflags2;  
    INTEGER sfhdr.stackhdr.aknumb1;  
    INTEGER sfhdr.stackhdr.aknumb2;  
};

Members

nxtqptr
Pointer to next buffer header.

hdreptr
Pointer to buffer element (NIL).

numelts
Number of buffer elements (0x00).

msgtype
Message type STATFMI (0x21).

srcl
Source locality.

srcp
Source partner.

srci
Source index.

destl
Destination locality.

destp
Destination partner.

desti
Destination index.

sfhdr.stackhdr.akstat
Status type ACK (0x01).

sfhdr.stackhdr.akqual
Acknowledgment type ACKNEG2 (0x04).

sfhdr.stackhdr.akmsgkey
Message key.

sfhdr.stackhdr.akflags1
Reserved.

sfhdr.stackhdr.akflags2
Critical failure indicator.

Noncritical failure (0x00) Critical failure (0x01)

sfhdr.stackhdr.aknumb1
Error code 1.

sfhdr.stackhdr.aknumb2
Error code 2.

Remarks

  • The Status-Acknowledge(Nack-2) message consists of a buffer header only. There is no buffer element.

  • The message key refers to the message key in the inbound data message to which this is a negative acknowledgment.

  • For more information about error codes, see Error and Sense Codes.