Production line remote monitoring

Engineering and IT Insight: Automation engineers spend a lot of time just getting to the right place to identify and fix problems. The IT solution to this problem is based on VNC, or virtual network computing.

04/01/2010


More automation systems and physically separated production lines mean that automation engineers spend a lot of time just getting to the right place to identify and fix problems. Time is also spent travelling to your automation lab to test theories and fixes, watching for “unreproducible” problems by looking over the shoulders of operators to determine exactly what they are doing and why the system is not doing what it is supposed to do. Add in time to monitor multiple systems during critical production times, such as startup, shutdown, and product switchovers, and a lot of time is spent getting in front of the right screens.

 

The IT solution to this problem is based on VNC, or virtual network computing. VNC is a desktop sharing system that is based on the remote frame buffer (RFB) protocol. It allows one computer to control, share, or view the desktop of another computer. Think of VNC as Microsoft’s Remote Desktop on steroids and based on an industry standard. For example, using a VNC system, you can remotely monitor a specific production line operator interface (HMI) in a separate window on your desktop. A VNC system captures screen changes on the remote computer, sends them to your screen, and sends local keyboard and mouse events to the remote computer.

 

VNC uses the RFB protocol for remote access to graphical user interfaces. The current specification is RFB 3.8, published in June 2007 by RealVNC Ltd. and is an industry standard. RFB works at the framebuffer level and does not require any application changes, allowing it to work with most windowing systems including X11, Windows and Macintosh. The RFB protocol is based on TCP/IP, can work through protected firewall ports, and contains security checks so that only authorized users can remotely connect. Most VNC implementations provide build-in encryption and screen compression, allowing both secure and effective operation across 10MB Ethernet links. With 100MB links, you cannot even tell you are operating a remote computer.

 

VNC has two parts: a server that is installed on the remote computer, and a viewer that is installed on the local computer. The server part does not have to run on a server operating system; it can be installed on Microsoft Windows XP, Windows Vista, Windows 7, Mac O/S, Linux, Windows Server 2000, and Windows server 2008. Viewers can be run from almost any desktop system.

 

A typical implementation is to install a VNC server on all of your HMI, programming, and lab systems. Then, from your desk, you can remotely connect to view, share, or control the remote computer. This eliminates trying to troubleshoot by a phone. If administrative access is needed to fix a problem, you can log in to the remote computer using an administrative account, perform the actions, and not have to physically travel to the production line. If you are monitoring multiple systems, you can make multiple remote connections and tile the screens to see them all at the same time, providing an inexpensive multiple-monitor system.

 

RealVNC and TightVNC provide free VNC versions that can be used for evaluation, and also provide inexpensive licensed versions. There are also many other free and commercial VNC solutions available.

 

VNC is an IT solution that solves a real problem for automation engineers. It allows you to effectively support multiple remote systems, reduces travel, and should be a part of every manufacturing IT solution.

 

References

For more information:

RealVNC www.realvnc.com

TightVNC www.tightvnc.com

Comparison of free and commercial VNC software: en.wikipedia.org/wiki/Comparison_of_remote_desktop_software.

 

 

 

Author Information

Dennis Brandl is president of BR&L Consulting in Cary, NC, www.brlconsulting.com . His firm focuses on manufacturing IT. Contact Dennis at dbrandl@brlconsulting.com .



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