SIGLENT
140 SSG5000X Programming Guide
End
If
' Now we will open VISA sessions to all USB TMC instruments.
' We must use the handle from viOpenDefaultRM and we must
' also use a string that indicates which instrument to open. This
' is called the instrument descriptor. The format for this string
' can be found in the function panel by right clicking on the
' descriptor parameter. After opening a session to the
' device, we will get a handle to the instrument which we
' will use in later VISA functions. The AccessMode and Timeout
' parameters in this function are reserved for future
' functionality. These two parameters are given the value VI_NULL.
For
i = 0
To
numInstrs
If
(i > 0)
Then
status = viFindNext(findList, instrResourceString)
End
If
status = viOpen(defaultRM, instrResourceString, VI_NULL, VI_NULL, instrsesn)
If
(status < VI_SUCCESS)
Then
resultTxt.Text = "Cannot open a session to the device " +
CStr
(i + 1)
GoTo
NextFind
End
If
' At this point we now have a session open to the USB TMC instrument.
' We will now use the viWrite function to send the device the string "*IDN?",
' asking for the device's identification.
status = viWrite(instrsesn, "*IDN?", 5, retCount)
If
(status < VI_SUCCESS)
Then
resultTxt.Text = "Error writing to the device."
status = viClose(instrsesn)
GoTo
NextFind
End
If
' Now we will attempt to read back a response from the device to
' the identification query that was sent. We will use the viRead
' function to acquire the data.
' After the data has been read the response is displayed.
status = viRead(instrsesn, Buffer, MAX_CNT, retCount)
If
(status < VI_SUCCESS)
Then
resultTxt.Text = "Error reading a response from the device." +
CStr
(i + 1)
Else
resultTxt.Text = "Read from device: " +
CStr
(i + 1) + " " + Buffer
End
If
status = viClose(instrsesn)
