Daqdevicemanager.createdevice(), Createdevice() – Measurement Computing DAQFlex User Guide User Manual

Page 25

DAQFlex Software User's Guide

DAQFlex Software Reference

If using a device that does not have an ID assigned, you must use the

NameOnly

NameAndSerno

format with the DaqDeviceManager.CreateDevice() method in order to create the device. A device

with no ID will not be created when using the

NameAndID

and

NameSernoAndID

format with

CreateDevice().

DaqDeviceManager.CreateDevice()

Creates a DaqDevice object. The DaqDevice object contains the methods used to configure, read data

from, or write data to a device. With the DaqDevice object, all DAQ operations are configured using one
API method called

DaqDevice.SendMessage()

rather than using multiple operation-specific methods.

SendMessage() takes a single parameter called message. This parameter is a text-based command that

the DAQ device parses to configure a particular operation.

C#:

static CreateDevice(string deviceName);

VB:

Shared Function CreateDevice(ByVal deviceName As String) As DaqDevice

Parameter

deviceName

One of the device names returned by the DaqDeviceManager.GetDevicenames() method.

Return value

An instance of a

DaqDevice object

Remarks



Depending on the DeviceNameFormat, the CreateDevice() method creates a DaqDevice object for

the device whose name, name and serial number, name and id, or name, serial number and id are

contained in the deviceName parameter.



The resources associated with the DaqDevice object can be freed by calling the

ReleaseDevice()

method.



The CreateDevice() method can only be called once for a specific device, unless the ReleaseDevice()

method is called.



If CreateDevice() is called more than once for a specific device without calling ReleaseDevice(), the

DaqDevice object

throws an exception

, indicating that a driver handle has already been created for

the device.

Refer to the following sample code:

try
{

MyDevice = DaqDeviceManager.CreateDevice(deviceName);

}

catch (Exception ex)

{

// handle exception
}

Try

MyDevice = DaqDeviceManager.CreateDevice(deviceName)

Catch Ex As Exception

' handle exception

End Try