Detailed explanation of remote control of LeCroy oscilloscope

In some specific occasions, such as in environmental test rooms, the ambient noise may reach 80 decibels to 90 decibels, and engineers should not work in such an environment for a long time; or when debugging in a different place, the instrument needs to be operated remotely; in addition, in order to improve work efficiency, the computer can replace the engineer to complete some simple traversal tests, for example, traversing the output voltage of the device under test and measuring the amplitude of the output waveform. These automated tests can greatly improve the test efficiency. To do this, it is necessary to be able to remotely control the oscilloscope.

At present, the commonly used remote control methods are as follows: 1. Use the remote desktop control (mstsc) that comes with Windows; 2. Use LeCroy's software for remote operation; 3. Remotely control the oscilloscope through programming. The following describes the three remote control methods respectively.

Before remotely controlling the oscilloscope, you need to set the oscilloscope and the host computer to the same network segment and be able to ping each other. In some cases, because the Windows firewall may block remote control or, it is recommended to disable the oscilloscope's Windows firewall before actual operation. The specific operation method is as follows:

Start menu, Control Panel, System and Security, Windows Firewall, Turn Windows Firewall on or

off, turn off Windows Firewall.

1. Remote desktop control

Remote Desktop Control is a component provided by Microsoft since Windows 2000 Server. When a computer has the Remote Desktop connection function enabled, we can operate and control the computer from the other end of the network. We can use Remote Desktop Control to control the computer in real time, install software on it, and run programs1.

When using a remote desktop connection, you need to enable remote control of the oscilloscope. The specific operation method is as follows:

Start menu, right-click Computers, select properties, Remote Settings, Remote Desk, select the second option to enable remote desktop connection, as shown in Figure 1. This way, you can use the PC to perform remote desktop control on the oscilloscope.

How to implement remote desktop control:

Windows key + R key, enter mstsc, enter the oscilloscope's IP address, enter the oscilloscope's user name and password, and you can achieve complete remote control of the oscilloscope through the PC. As shown in Figure 2:

It should be noted that many large companies have office computers joined to a domain. When enabling a remote desktop link, the default is generally the domain where the local computer is located. Therefore, when entering the oscilloscope username, you need to add a backslash "" in front of the username (if the PC is not added to the domain or the oscilloscope is also joined to the same domain, this is not necessary). The default username of the oscilloscope is LeCroyUser and the default password is lecroyservice.

In the case of remote desktop control, the operator is usually far away from the oscilloscope, so the key panel on the right side of the oscilloscope cannot be used. Some common functions such as Default Setup or Auto Scale are not very convenient to use. In this case, it is recommended to call out the virtual panel. The specific method is as follows:

Open the Wave Studio software on the desktop, click the "Add Scope" button, select "Network", enter "127.0.0.1", and click
the "Show Remote FrontPanel" button, as shown in Figure 3. At this time, a virtual panel that is the same as the button panel on the right side of the oscilloscope will appear.

Figure 1 Enabling remote desktop control

Figure 2 Schematic diagram of remote desktop connection

Figure 3 Opening the virtual front panel

2. Use the software provided by LeCroy for remote control

The Wave Studio software provided by LeCroy can realize simple control of the oscilloscope. It can realize horizontal and vertical scale adjustment, trigger mode selection, waveform acquisition and other functions through the network or USB interface. QualiPHY software can remotely control the oscilloscope to complete the compliance test. This article will introduce how to use TCPIP to realize remote control of the oscilloscope, which is divided into 3 steps:

a) Select TCPIP for the remote control of the oscilloscope

. Enter the main interface of the oscilloscope, Utilities Setup, Remote, Control From, select "TCPIP (VICP)", as shown in Figure 4.

Figure 4 Select remote control mode

b) Use Wave Studio to connect to an oscilloscope.

Download Wave Studio software and install it from:

Open the Wave Studio software on the desktop, click the “Add Scope” button, select “Network”, enter the IP address of the oscilloscope, and if the connection is normal, you will see Figure 5 in the lower left corner of the window.

We can find the waveforms in each channel/operation or storage we need from Trace, and save the waveform files locally. Display Capture can display the current interface of the oscilloscope in Wave Studio.

Figure 5 Instrument connection successful

Scope Setups can configure the settings saved in the computer to the oscilloscope, Mass Storage can view the various files in the oscilloscope's hard disk, and Front Panel can call up the virtual front panel.

c) Use QualiPHY for remote conformance testing

Download and install the QualiPHY software from:

Open the QualiPHY software on the desktop, General Setup, Connection, enter the IP address of the oscilloscope, click "Close",
select the protocol to be tested, configure it, and then you can start the consistency test.

It should be noted that when using QualiPHY remotely and using QualiPHY testing on an oscilloscope, the oscilloscope needs to have the corresponding software options. For example, if you need to measure USB 3.0, the controlled oscilloscope needs to have the QPHY-USB3 option.

3. Programming control of oscilloscope

When it comes to program control, two aspects are involved: one is the communication method, or more precisely, how the commands are transmitted to the oscilloscope; the other is the communication commands, that is, replacing the various operations of the oscilloscope with text commands, and how we find these commands.

When it comes to instrument control, the most commonly used one is NI-VISA from National Instrument. The full name of VISA is Virtual Instrument
Software Architecture. It is a software package for virtual instrument development and instrument control. VISA supports multiple communication methods such as LXI, VXI, USB, GPIB and RS232. Basically, all programmable instruments can be controlled using NI-VISA, and it supports multiple operating systems such as Windows, Linux and Mac OS. VISA supports multiple programming platforms such as C/C++, VB, LabVIEW2, MatLab, Python and .Net Framework. Commonly used functions are (take C# as an example, the same below, the names in different programming languages ​​will be different, but the functions are similar): Open, used to open the instrument session; Close, used to close the instrument session; Write, used to send commands to the instrument; Query, used to send commands to the instrument and obtain the return value, which can be used to obtain the measured value or instrument status. The latest version of NI-VISA is 15.5, which can be downloaded for free on the official website of NI3. Regarding how to use NI-VISA to control instruments, NI's official website has detailed instructions4, which will not be discussed in detail in this article.

To use NI-VISA to control the LeCroy oscilloscope, some configuration is required on the oscilloscope side. If you need to use the network port to control the oscilloscope, you need to configure the oscilloscope to LXI (VXI11) mode. If you need to use GPIB to control the oscilloscope, you need to select GPIB mode. The configuration method is similar to part a) in Section 2.

In addition to NI-VISA, LeCroy also provides similar software called ActiveDSO. ActiveDSO can control the oscilloscope through TCPIP and GPIB, and supports multiple programming languages ​​such as MatLab, VB/VBA, VC++, Java, and .Net Framework. Compared with NI-VISA, ActiveDSO is compact and powerful: the installation package size of NI-VISA is more than 500MB, while ActiveDSO is less than 2MB; in addition, ActiveDSO provides specific functions to facilitate direct reading of waveform data and measurement parameters. Download address of ActiveDSO:

ActiveDSO provides the following commonly used functions5:

MakeConnection: Used to open an instrument session, similar to the Open function of NI-VISA.

WriteString: Used to send commands to the instrument, similar to the Write function of NI-VISA.

ReadString: used to read data from the instrument. It is usually used together with WriteString. Together, it is similar to the Query function of NI-VISA.

Disconnect: Used to close the instrument session, similar to the Close function of NI-VISA.

In addition, ActiveDSO also provides functions such as GetByteWaveform, GetIntegerWaveform, and GetScaledWaveform. Through these functions, the value of each point in the waveform of the oscilloscope can be directly read into the program, which is convenient for further analysis of the waveform. In addition, ActiveDSO provides examples of VBA, MatLab, VBS, and VC++. After installing ActiveDSO, you can find it in the Start menu, All Programs, LeCroy, ActiveDSO.

The above-mentioned NI-VISA and ActiveDSO are both platforms for realizing communication between PC and oscilloscope. Software engineers can use these platforms to send commands to oscilloscopes, but which specific command corresponds to which operation, generally need to be queried from the instrument programming manual. In addition to the programming manual, LeCroy also provides a method to query programming instructions, that is, through the software that comes with the instrument - XStream Browser. The commands of LeCroy's full range of oscilloscopes with operating systems can be searched through XStream Browser, and the programming commands are universal for the entire series (limited to universal commands, some commands related to software options depend on whether the current oscilloscope contains this software option. If this software option is not included, it cannot be used). Therefore, the code is highly portable, and it is easy for two oscilloscopes of different models and platforms to use the same underlying code.