The following white paper describes the use of Microsoft's Windows XP Remote Desktop to control a PXI system from a remote PC, such as a laptop. It explains the benefits of using XP Remote Desktop and provides an overview of the system setup. In addition, it addresses some important topics related to remotely controlling a PXI system including file sharing, performance issues, and connection settings. Figure 1 below depicts a typical setup for using XP Remote Desktop to control a PXI system. For instructions on how to set up such a system, please refer to related link How Can I Use XP Remote Desktop to Control My PXI System with a Laptop?
Figure 1. Example Remote System Setup
2. Benefits of Using XP Remote Desktop
The concept of using a remote setup to control your PXI system implies that you have the ability to place a measurement system in any location, such as a lab. This system then can be controlled from another computer at a different location, such as your office in another building, provided both the PXI controller and the client computer are connected to an established network. You can use the PXI system as a measurement environment that is controlled via a remote session initiated from somewhere else on the network. Using the XP Remote Connection software from a client laptop, you can control measurement and automation systems that are in remote regions or in inaccessible and hazardous areas.
There are several benefits to working with the XP Remote Desktop to remotely control your PXI system. By using the XP Remote Desktop you take advantage of existing Microsoft technology to control your PXI system easily over a network. You can simply reuse existing network architectures, such as the Ethernet or 802.11. In addition, users have the benefit of working in a familiar Windows environment compatible with all National Instruments products. Lastly, by using a laptop to control your PXI system, you have a more compact means of providing a monitor, keyboard, and mouse for applications where portability is a required feature.
Windows XP Remote Desktop uses Remote Data Protocol (RDP) to provide remote terminal sessions to clients. Only the mouse, keyboard, and video information from the terminal session is transmitted. Although this information is encrypted, it is still possible to experience security vulnerability. For more information, please refer to the Microsoft Security Bulletin in the Related Links section. Additional precautions can also be taken through the use of standard network security products.
For alternative methods to control the PXI system from a PC, please refer to the related link Laptop Control of PXI over Ethernet.
Note: If your application requires more reliable and deterministic results, it would be more appropriate to move to a Real-Time environment.
3. System Overview
The test system consisted of two main parts – the PXI system and the client computer. The PXI system consisted of an AC-powered NI PXI-1042 chassis equipped with an NI PXI-8176 embedded controller. The controller was loaded with Windows XP Professional and 256 MB RAM, the recommended minimum to run Windows XP Professional efficiently on a PXI-8176 controller. The relevant software loaded on the PXI-8176 includes NI LabVIEW 7.0, NI-DAQ 7.0 and NI-IMAQ 2.6.
The client computer used was an Intel Pentium III 1 GHz PC with 256 MB of RAM running Windows 2000 SP2. These computers were connected over the National Instruments network via a 100BaseT Ethernet connection.
The extra equipment used to test the performance of XP Remote Desktop includes the PXI-6070E, PXI-6115, PXI-1407, and an RS-170 monochrome camera and power adapter. Figure 1 in the Introduction section illustrates a possible setup using XP Remote Desktop with PXI.
Note: When initially setting up your PXI system you must still complete the preliminary configuration with a keyboard, mouse, and monitor. This process is necessary to enter the Product Key, for example. Once that step is completed, you can move to a headless configuration. For more information on setting up the system, refer to the KnowledgeBase article listed in the Introduction section of this document. This KnowledgeBase article also contains important information on proper reboot and shutdown techniques. It is very important to properly shut down the PXI controller. If you do not correctly shut down the controller, it will take longer to boot up your system the next time you power the chassis and Windows scans the hard disk after an improper shutdown. In addition, an improper shut down can result in operating system corruption.
4. File Sharing
File sharing can be simply defined as the ability to access data on one computer from another computer on a network. With respect to using XP Remote Desktop to control a PXI system, this refers to the ability to access data on the PXI controller from your client PC, or vice versa.
File sharing is very easy to set up using the built in features of XP Remote Desktop. Before connecting to the remote session from your client PC, simply click on the Options button as shown in Figure 2 below.
Figure 2. Connecting to Remote Session via Windows Client
Select the Local Resources tab and enable the Disk drives check box as shown in Figure 3.
Note: You also have the ability to share other resources, such as printers and serial ports. After clicking on the Connect button and logging into your PXI controller, you are now able to share data between your remote PXI chassis and your client machine.
Figure 3. Local Resource Option in Remote Desktop Connection
With the file sharing feature enabled, you can access all of the local client drives from the remote session. These drives are mapped and visible from the My Computer icon on the remote session desktop. In addition, you also can cut and paste files from the client machine to your remote session (and vice versa).
Note: If you are using a Macintosh client to remotely control your PXI system, you can still use the file-sharing feature. The Macintosh client drives are mapped on your remote session. However, you can cut and paste only text, not files, between the Mac client and the XP remote session.
Finally, an alternative method to perform file transfers is to use the standard FTP (File Transfer Protocol) network protocol. There are several Developer Zone documents with detailed information on using FTP with National Instruments products such as PXI and LabVIEW Real-Time.
5. Performance Issues
During the initial testing of XP Remote Desktop controlling the PXI system, no performance issues were encountered. Remember that the applications are running directly on the PXI system and are using the resources of the PXI controller. Only the graphical user interface (GUI) information is transmitted through the remote session, and no performance issues were expected. Nonetheless, the following tests were performed over the National Instruments network with the equipment listed in the Overview. In all tests, the connection setting for the XP Remote Session was set to LAN. Please see the Connection Settings section for more information on this setting.
- Ran the example program ActiveX Event Callback for IE.vi and verified that ActiveX controls run correctly over the XP Remote Desktop session.
- Ran the example program 3D Surface Example – Fluctuating Sine Wave.vi and verified 3D graph controls run correctly over the XP Remote Desktop session.
- Ran the example program Cont Acq&Graph Voltage-Int Clk.vi with the highest sampling rate, 1.25 MS/s using the PXI-6070E DAQ module, and verified there was no performance degradation over the remote session.
- Tested with two PXI-6115 DAQ modules running a benchmarking VI with some graphical data, verified that the program ran successfully, and benchmarked the same throughput as seen when run locally. This test shows that there is no impact in running the VI through the remote session.
- Tested the Snap and Grab functions within MAX using the PXI-1407 image acquisition module and RS-170 monochrome camera and verified that it ran correctly over the XP Remote Desktop Session. Also ran the example programs HL Snap.vi and HL Grab.vi and verified that they both ran correctly over the remote session.
6. Connection Settings
As previously mentioned, XP Remote Desktop uses RDP to provide remote terminal sessions to clients on the network and transmits only the GUI information. Depending on the type of connection you have, different connection speeds can be chosen to optimize the performance of your connection. The connection speed options can be accessed before connecting to the remote session from your client laptop by clicking on the Options button as shown in Figure 2 in the File Sharing section. From here, click on the Experience tab as shown in Figure 4 below.
Figure 4. Speed Options in Remote Desktop Connection
Within this tab, you can specify the connection speed by selecting one of the options in the drop down menu as shown in Figure 4. The available selections are as follows.
- Modem (28.8 kbps)
- Modem (56 kbps)
- Broadband (128 kbps - 1.5 Mbps)
- LAN (10 Mbps or higher)
For example, if you have a high-bandwidth network connection, you can select the LAN connection speed. By default this selection allows the most information to be transferred. Alternatively, if you are working over a 56 kbps modem, you can perform Themes and Bitmap caching only, optimizing the performance of the remote connection.
KB 2Y5FNQOK: How Can I Use XP Remote Desktop to Control My PXI System With a Laptop?
KB 4YFEDIQ7: Network Settings For Using Windows XP Remote Desktop With A PXI Controller
Laptop Control of PXI over Ethernet
Microsoft Security Bulletin: Cryptographic Flaw in RDP Protocol Can Lead to Information Disclosure