If you are using Windows and have the National Instruments ni488 drivers with VISA.net loaded it is easy to talk to instruments from MATLAB without using the Instrument Control Toolbox.
>> ni=NET.addAssembly('NationalInstruments.VisaNS')
ni =
NET.Assembly handle Package: NET
Properties for class NET.Assembly:
AssemblyHandle
Classes
Structures
Enums
GenericTypes
Interfaces
Delegates
>>
The variable "ni" contains useful information about the properties of the NET.Assembly such as which enumerations are available.
We can now use the methods located in this assembly.
>> res=NationalInstruments.VisaNS.ResourceManager.GetLocalManager.FindResources('?*').cell
res =
'ASRL1::INSTR' 'ASRL2::INSTR' 'ASRL10::INSTR' 'GPIB0::INTFC' 'GPIB0::25::INSTR'
>>
if you type "res=Nat" then press tab you will see that tab completion works! In my case res{5} is the string that identifies the device that I want to open.
>> dev=NationalInstruments.VisaNS.ResourceManager.GetLocalManager.Open(res{5})
dev =
GpibSession with properties:
ReaddressingEnabled: 1
UnaddressingEnabled: 0
AllowDma: 0
PrimaryAddress: 25
RenState: [1x1 NationalInstruments.VisaNS.LineState]
SecondaryAddress: -1
ReadToFileAppends: 0
DefaultBufferSize: 16384
IOProtocol: [1x1 NationalInstruments.VisaNS.IOProtocol]
SendEndEnabled: 1
TerminationCharacter: 10
TerminationCharacterEnabled: 0
HardwareInterfaceName: [1x1 System.String]
HardwareInterfaceNumber: 0
HardwareInterfaceType: [1x1 NationalInstruments.VisaNS.HardwareInterfaceType]
LastStatus: [1x1 NationalInstruments.VisaNS.VisaStatusCode]
ResourceClass: [1x1 System.String]
ResourceImplementationVersion: 5243904
ResourceLockState: [1x1 NationalInstruments.VisaNS.AccessModes]
ResourceManufacturerID: 4086
ResourceManufacturerName: [1x1 System.String]
ResourceName: [1x1 System.String]
ResourceSpecificationVersion: 5243136
Timeout: 3000
VisaEventQueueLength: 50
SynchronizingObject: []
Handle: [1x1 System.IntPtr]
SynchronizeCallbacks: 1
NoSecondaryAddress: -1
>>
Now I can talk to the device.
>> dev.Query('*IDN?')
ans =
Agilent Technologies,33250A,0,2.04-1.01-2.00-03-2
or I can use Write and ReadString
>> dev.Write('*IDN?')
>> dev.ReadString
ans =
Agilent Technologies,33250A,0,2.04-1.01-2.00-03-2
You need to be aware that the return type will be system.string so you may want to convert it to char so that you can use functions such as str2double().
>> x=dev.Query(':FREQ?')
x =
+1.0000000000000E+03
>> whos x Name Size Bytes Class Attributes
x 1x1 112 System.String
>>
>> x=dev.Query(':FREQ?').char
x =
+1.0000000000000E+03
>> whos x Name Size Bytes Class Attributes
x 1x21 42 char
>>
>> x=str2double(dev.Query(':FREQ?').char)
x =
1000
>> whos x Name Size Bytes Class Attributes
x 1x1 8 double
>>
To release the device and free the resource:
>> dev.ControlRen(NationalInstruments.VisaNS.RenMode.AddressAndGtl)
>> dev.Dispose
You can also read block data and handle service requests.
