The question frequently comes up for which is better, the PC based (Windows based) HMI or a hardware based. There are clear advantages to each. As with most things the decision comes down to the application. These are a few items that can help in making the decision.
- Security – Hacking and virus infection is always a top question when it comes to Windows based PCs. It is generally considered that hardware based HMIs are safe from these attacks. Windows is well known for infections and attacks, so it does require an extra layer of security. A very easy way to protect the HMI is to not give it direct internet access. You may also want to prevent operators from accessing the USB ports if there is a concern of someone possibly slipping a infected drive in.
- Maintainability – The life cycle of a product is generally very important in industrial settings where machine life can easily exceed 10 years. Electronics are notorious for having a very short life. This is where PC based has a strong advantage. By not being locked in to a proprietary hardware, you have other options when the current hardware is no longer available. Windows software forward compatibility can be an issue also, but stands a better chance of working on a new OS than would a proprietary software on the next generation of hardware, and that would be IF there is a next generation. AdvancedHMI attempts to give the longest life cycle by being based on the .NET framework which s backed by Microsoft and now an open source platform used in a large number of applications.
- Serviceability – When it comes to a Windows based PC, there is a very good chance that someone is close by that knows at least a little about it. With proprietary hardware, you will be hard pressed to find someone near by that has much knowledge about it.
- Cost – In the past a PC based HMI has been more expensive because of the hardware requirement and the cost of software license. AdvancedHMI has turned the table on this with its license model. It is now lower in cost to use a PC based HMI if using AdvancedHMI.
- Flexibilty/Capability – A PC based HMI has a clear advantage on this simply because of the range of available applications that can be loaded on the PC. One such example is a VNC for remote control. PC based can also give you advanced features such as database interaction.
- Support – If it comes to hardware or the OS support, a PC based HMI has the clear advantage. With the software, this will vary widely. AdvancedHMI steps ahead in this category by being open and based on a widely used platform. Although the support forum for AdvancedHMI is very active, you can find support by going to any .NET or Visual Studio forums which gives hundreds of options.
Another thing to consider is that a PC based system gives you more options by a large gap. You can choose how fast and responsive you want the system to be by selecting which processor, how much memory, how much you put in your system. In proprietary hardware, you are locked into what the manufacturer decides you need. If your application grows, it may become sluggish and your are stuck.