# WMStartMPCallback

## Definition

  `#include <nitro/wm.h>`

      typedef struct WMStartMPCallback
      {
          u16         apiid;
          u16             errcode;
          u16         state;
          u8            reserved[2];
          WMMpRecvBuf*    recvBuf;
          u16             timeStamp;
          u16             rate_rssi;
          u16             destAdrs[3];
          u16             srcAdrs[3];
          u16 seqNum;
          u16             tmptt;
          u16             pollbmp;
          u16             reserved2;
      } WMStartMPCallback;

## Elements

`apiid` | ID of the API that acts as the source for the callback generation. It is equivalent to the `WMApiid` enumerated type. Here, it is fixed as `WM_APIID_START_MP`.
`errcode` | Result of the asynchronous process. It is equivalent to the `WMErrCode` enumerated type.
`state` | If `errcode` is `WM_ERRCODE_SUCCESS`, the WM Cause Code generated by the callback is stored. There are four causes: `WM_STATECODE_MP_START`, `WM_STATECODE_MPEND_IND`, `WM_STATECODE_MP_IND` and `WM_STATECODE_MPACK_IND`. Among the error codes listed, normally `WM_STATECODE_MP_START` is the only one that the application needs to process.
`recvBuf` | If `state` is `WM_STATECODE_MPEND_IND` or `WM_STATECODE_MP_IND`, a pointer to the receive data storage destination will be stored. The receive buffer specified in `WM_StartMP` is handled as a double buffer. This indicates which of the buffers will be the first data storage destination. When a machine accepts data as a parent, this will be a pointer to the `WMMpRecvHeader` type.

`timeStamp
rate_rssi
destAdrs
srcAdrs
seqNum
tmptt
pollbmp`

When `state` is `WM_STATECODE_MPACK_IND`, each of the arguments stores the information on the MP communication that was performed.

## Description

This structure is passed to the callback function for the `WM_StartMP` and `WM_StartMPEx` functions.

## Revision History

2007/07/18 Added text about `state`.
2004/08/11 Added members to be stored at the time of MP completion callback.
2004/08/02 Standardized structure names.
2004/07/29 Initial version.

CONFIDENTIAL