Measurement-computing DAQFlex User Guide Manuale Utente Scaricare il pdf (Pagina 26)

DAQFlex Software User's Guide DAQFlex Software Reference

DaqDeviceManager.ReleaseDevice()

Frees the resources associated with a DaqDevice object.

C#:

static void ReleaseDevice(DaqDevice device);

VB:

Shared Sub ReleaseDevice(ByVal device As DaqDevice)

Parameter

Device

A DaqDevice object created by the CreateDevice() method.

DaqDevice class

The DaqDevice class includes the following methods:

 SendMessage() – takes a single text-based command that the DAQ device parses to configure a

particular operation.

 ReadScanData() – reads scan data.

 WriteScanData() – outputs scan data.

 EnableCallback() – enables a user-defined callback method to be invoked when a certain condition

is met. This method is used in conjunction with input scan operations.

 DisableCallback() – the condition that invokes the callback method.

 GetErrorMessage() – gets the error message associated with the error code that is passed to the

user-defined callback.

 GetSupportedMessages() – returns a list of messages supported by a DAQ component.

DaqDevice.SendMessage()

Configures DAQ operations. This method takes a single text-based command that the DAQ device

parses to configure a particular operation.

C#:

DaqResponse SendMessage (string message);

VB:

Function SendMessage (ByVal Message as String) As DaqResponse

Parameter

Message

The text-based message to send to the device.

Return value

The device response as an instance of a DaqResponse object.

Remarks

 Message is a string containing a text-based command supported by the device, and Response is a

DaqResponse object containing the device's response.

 The DaqResponse object includes two methods:

 ToString(): gets the response as a string, for example "AI{0}:VALUE=139".

 ToValue(): gets the response as a numeric value, for example "139.0000".

 All messages provide a string response, but not all messages provide a numeric response. For those

messages that do not provide a numeric response, the numeric value is set to NaN (not a number).

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Measurement-computing DAQFlex User Guide Manuale Utente Pagina 26