Data Acquisition Toolbox

propinfo

Return property characteristics for device objects, channels, or lines

Syntax

out = propinfo(obj)
out = propinfo(obj,'PropertyName')

Arguments

obj	A device object, channels, or lines.
'PropertyName'	A valid obj property name.
out	A structure whose field names are the property names for obj (if PropertyName is not specified).

Description

out = propinfo(obj) returns the structure out whose field names are the property names for obj. Each property name in out contains the fields shown below.

Field Name	Description
Type	The property data type. Possible values are action function, any, double, and string.
Constraint	The type of constraint on the property value. Possible values are action function, bounded, enum, and none.
ConstraintValue	The property value constraint. The constraint can be a range of valid values or a list of valid string values.
DefaultValue	The property default value.
ReadOnly	If the property is read-only, a 1 is returned. Otherwise, a 0 is returned.
ReadOnlyRunning	If the property is read-only while the device object is running, a 1 is returned. Otherwise, a 0 is returned.
DeviceSpecific	If the property is device-specific, a 1 is returned. If a 0 is returned, the property is supported for all device objects of a given type.

out = propinfo(obj,'PropertyName') returns the structure out for the property specified by PropertyName. If PropertyName is a cell array of strings, a cell array of structures is returned for each property.

Example

Create the analog input object ai for a sound card and configure it to operate in stereo mode.

ai = analoginput('winsound');
addchannel(ai,1:2);

To capture all property information for all common ai properties

out = propinfo(ai);

To display the default value for the SampleRate property

out.SampleRate.DefaultValue
ans =
        8000

To display all the property information for the InputRange property

propinfo(ai.Channel,'InputRange')
ans = 
               Type: 'double'
         Constraint: 'Bounded'
    ConstraintValue: [-1 1]
       DefaultValue: [-1 1]
           ReadOnly: 0
    ReadOnlyRunning: 1
     DeviceSpecific: 0

See Also

Functions

daqhelp

peekdata

putdata