# dtmAttachTrunkMonitor

Enables an application to attach to a trunk monitor service object created by another application when dtmStartTrunkMonitor is invoked.

#### Prototype

DWORD dtmAttachTrunkMonitor ( CTAHD ctahd, unsigned board, unsigned trunk, DTMHD *dtmhd)

Argument | Description
ctahd | Handle returned by ctaCreateContext or ctaAttachContext.
board | Board number.
trunk | Specified trunk on the board. The first trunk is 0.
dtmhd | Pointer to the returned trunk monitor object handle.

#### Return values

Return value | Description
SUCCESS |
CTAERR_BAD_ARGUMENT | Specified board or trunk is invalid or is not currently being monitored.
CTAERR_INVALID_HANDLE | Specified ctahd is invalid.
CTAERR_SVR_COMM | Communication error in server environment.

#### Details

dtmAttachTrunkMonitor enables an application to attach to a trunk monitor object created by another application. A DTM handle, dtmhd, is returned to the application calling this function. With this handle, the application can access the attached trunk monitor object.

The dtmhd is valid until the application receives DTM_MONITOR_DONE. Any applications sharing the trunk monitor can call dtmStopTrunkMonitor to stop monitoring. The corresponding DONE event is sent to all applications sharing the context. Upon receiving a DONE event with the same handle in the objHd field, the dtmhd becomes invalid.