Data Acquisition Toolbox

DataMissedFcn

Specify the M-file callback function to execute when data is missed

Description

A data missed event is generated immediately after acquired data is missed. This event executes the callback function specified for DataMissedFcn. The default value for DataMissedFcn is daqcallback, which displays the event type and the device object name.

In most cases, data is missed because:

• The engine cannot keep up with the rate of acquisition.
• The driver wrote new data into the hardware's FIFO buffer before the previously acquired data was read. You can usually avoid this problem by increasing the size of the memory block with the BufferingConfig property.

Data missed event information is stored in the Type and Data fields of the EventLog property. The Type field value is DataMissed. The Data field value is RelSample, which is the last sample acquired when the event occurred.

When a data missed event occurs, the analog input object is automatically stopped.

Characteristics

Usage	AI, Common
Access	Read/write
Data type	String
Read-only when running	No

Values

The default value is daqcallback.

See Also

Functions

daqcallback

Properties

EventLog

ClockSource

DefaultChannelValue