The TCP/IP interface is supported through a VISA-TCP/IP object.
The features associated with a VISA-TCP/IP object are similar to the
features associated with a tcpip
object. Therefore,
only functions and properties that are unique to VISA's TCP/IP interface
are discussed in this section. Both VXI-11 and HiSLIP protocols are
supported.
Refer to TCP/IP and UDP Comparison to learn about writing and reading text and binary data, using events and callbacks, and so on.
You create a VISA-TCPIP object with the visa
function. Each VISA-TCPIP object
is associated with an instrument connected to your computer.
visa
requires the vendor name and the resource name as input arguments. The
vendor name can be keysight
(note that
agilent
also still works), ni
,
rs
, or tek
. The resource name consists of
the TCP/IP board index, IP address or host name, and LAN device name of your
instrument. You can find the VISA-TCPIP resource name for a given instrument with
the configuration tool provided by your vendor, or with the instrhwinfo
function. (In place
of the resource name, you can use an alias as defined with your VISA vendor
configuration tool.) As described in Connecting to the Instrument, you can also
configure property values during object creation.
Before you create a VISA object, you must find the instrument in the appropriate vendor VISA explorer. When you find the instrument configured, note the resource string and create the object using that information. For example, to create a VISA-TCPIP object that uses National Instruments™ VISA associated with an instrument at IP address 216.148.60.170 using the VXI-11 protocol,
vt = visa('ni','TCPIP::216.148.60.170::INSTR');
The VISA-TCPIP object vt
now
exists in the MATLAB® workspace.
To open an connection to the instrument, type:
fopen (vt);
You
can display the class of vt
with the whos
command.
whos vt Name Size Bytes Class vt 1x1 886 visa object Grand total is 17 elements using 886 bytes
After you create the VISA-TCPIP object, the properties listed below are automatically assigned values. These properties provide descriptive information about the object based on its class type and address information.
VISA-TCPIP Descriptive Properties
You can display the values of these properties for vt
.
vt.Name ans = VISA-TCPIP-216.148.60.170
vt.RsrcName ans = TCPIP::216.148.60.170::INSTR
vt.Type ans = visa-tcpip
The VISA-TCPIP object provides you with a convenient display that summarizes important address and state information. You can invoke the display summary these three ways:
Type the VISA-TCPIP object at the command line.
Exclude the semicolon when creating a VISA-TCPIP object.
Exclude the semicolon when configuring properties using the dot notation.
You can also display summary information via the Workspace browser by right-clicking an instrument object and selecting Display Summary from the context menu.
The display summary for the VISA-TCPIP object vt
is
given below.
VISA-TCPIP Object Using NI Adaptor : VISA-TCPIP-216.148.60.170 Communication Address RemoteHost: 216.148.60.170 Communication State Status: closed RecordStatus: off Read/Write State TransferStatus: idle BytesAvailable: 0 ValuesReceived: 0 ValuesSent: 0
The VISA-TCPIP address consists of
Board index (optional, from the VISA configuration)
Remote host of the instrument
The protocol, either VXI-11 or HiSLIP
LAN device name of the instrument (optional)
You specify these address property values via the resource name during VISA-TCPIP object creation. The instrument address properties are given below.
VISA-TCPIP Address Properties
Property Name | Description |
---|---|
Specify the index number of the TCP/IP board in VISA configuration (optional — defaults to 0). | |
Specify the remote host name or IP address of the instrument. | |
Specify the LAN device name of the instrument. |
The properties are automatically updated with the specified resource name values when you create the VISA-TCPIP object.
You can display the address property values for the VISA-TCPIP
object vt
, created in Creating a VISA-TCPIP Object.
fopen(vt) vt.RemoteHost ans = 216.148.60.170