Detailed explanation of remote control of LeCroy oscilloscope

The instrument control commands are divided into three types. One is readable and writable, such as the vertical scale value of a channel. We can write to the oscilloscope through the program, and we can also read the current scale value from the oscilloscope through the program. The other is read-only, such as the result of a certain measurement parameter. These measurement values ​​can only be read from the oscilloscope through the program. There is also a write-only, also called Action, such as Default Setup. These are the commands we send to the oscilloscope, and reading them is meaningless. The steps to operate XStream Browser are as follows:

On the oscilloscope desktop, select XStream Browser, and then select “Connect to a local X-Stream DSO Device” (button under the file menu). You will get the interface shown in Figure 6:

Figure 6 XStream Browser interface

On the left side of the window is a list of the functions currently included in the oscilloscope in order from A to Z. Those related to acquisition are all in "Acquisition", such as channel settings, horizontal axis settings, sampling rate/storage depth settings, trigger mode, etc., are all in this column; those related to parameter measurement are all in "Measurement", and correspondingly, those related to function operations are all in "Math".

As shown in Figure 7, if we need to obtain or modify the coupling mode of channel 1, we can

Figure 7 Searching for commands through XStream Browser

Find the "Coupling" option in "C1" of "Acquisition", and you can see that the current value is "AC1M", which is a readable and writable parameter of enumeration type with 4 optional values. At the bottom of XStream Browser (status bar), the words "app.Acquisition.C1.Coupling" appear, which is the control command corresponding to the option "C1 channel coupling mode". Other control commands can also be found in a similar way.

The control command needs to be combined with the "VBS" command to operate the oscilloscope. The format of the VBS command is shown in Figure 8: Among them, the "automation command" is the command we found through the XStream Browser.

Let's take the coupling of channel 1 mentioned above as an example. Channel 1 is now in the "AC1M" coupling mode. Through NI-VISA, "VBS?

Return=app.Acquisition.C1.Coupling” to the oscilloscope and read the return value. You can get the result shown on the right side of Figure 9. Now channel 1 is in the “AC1M” coupling mode. If you need to change the coupling mode of channel 1, for example, to “DC1M”, you only need to use NI-VISA to change the pointer to

Figure 9 Controlling the oscilloscope via NI-VISA

Just send “VBS app.Acquisition.C1.Coupling = “DC1M”” to the oscilloscope. It should be noted that the data type corresponding to this instruction is an enumeration type, and DC1M must be enclosed in quotation marks; or we can directly enter numbers, DC50 /GND /DC1M /AC1M correspond to numbers 0~3 respectively; if the data type corresponding to the instruction is a Boolean type, True and False do not need to be enclosed in quotation marks, or we can also use numbers -1 and 0 instead.

When debugging a program, it is recommended to set the Log Mode in the oscilloscope to "Full Dialog" so that the oscilloscope can record every instruction it receives in the Log, as shown in Figure 10. This helps you check whether there is a problem with your program. The specific operation is as follows:

Figure 10 Event Log window, which helps us debug the program

Enter the oscilloscope main interface, Utilities, Utilities Setup, Remote, Remote Control Assistance, Log Mode, select "Full Dialog", as shown in Figure 11

Figure 11 Select to save all instructions in Log

The three methods of remote control of oscilloscopes have their own advantages and disadvantages. The remote desktop control that comes with Windows is simple and easy to use, but it takes up more network resources and has high bandwidth requirements, especially in non-LAN environments; the Wave Studio software provided by LeCroy is simple and takes up fewer resources, but it provides relatively few functions; writing programs to control the oscilloscope has high execution efficiency, can realize rich functions, and takes up relatively few network resources, but it has high requirements for engineers and requires engineers to have certain programming skills.

For a test engineer, learning to control an oscilloscope through programming can hand over many simple and repetitive tasks to the computer, which can greatly reduce the probability of misoperation and improve test efficiency. In addition, single-board control and oscilloscope control can be combined to achieve global automation and further improve test efficiency. Furthermore, being familiar with the programming instructions of the oscilloscope can make us more familiar with and understand the working mode and working principle of the oscilloscope, so that our own ability can be improved. If conditions permit, it is recommended that all test engineers try oscilloscope programming. Perhaps only a few lines of code can greatly improve our work efficiency.