Several of my recent clients have come with the same question and different outcomes. What sort of computer do we need for our measurement system?
The User-Driven Acquisition
One customer has a user-driven product. It is acquiring and analysing some data in real-time from some custom electronics. It needs to be quite powerful, but we need to be cost-conscious - this is taking a piece out of their profit on every system.
In this case, we went for standard PC hardware. The end-user operates the system in typical office hours (8 hours a day, 5 days a week) and a clean environment. This usage pattern means consumer hardware can be appropriate.
It has the bonus of being quite cost-effective, and we have been able to add upgrades as the system becomes more capable and requires more resources.
The operating system is Windows. Customers are familiar and comfortable with it. We don't mind having to update overnight, and LabVIEW has excellent support for interactive installers for upgrading the software over time.
User-driven applications are much more forgiving
The Low Power, Reliable Control System
Another customer is building a product which is going into a manufacturing environment, so reliability is vital. Reboots for updates is an absolute no-no, and the system needs to run 24/7 in possibly dusty and dirty environments.
The application isn't too demanding, so in this case, we went to an industrial PC.
These generally vary from low power processors up to desktop PC performance but are designed with high-reliability components and fanless design to keep the system running 24/7 in a variety of conditions.
In this case, because of the control aspects as well we wanted to run LabVIEW Real-Time as the operating system so we could bring existing LabVIEW code into an embedded system. Therefore we used a National Instruments Industrial Controller. Another option would be a cheaper industrial computer from suppliers such as On Logic - however, we lose some of the features of the LabVIEW Real-Time OS which we wanted to use in this case.
NI Industrial Control Products
The High Powered 24/7 Measurement System
The final customer was also looking at 24/7 running of a measurement system. In this case, storing measurements for future analysis. (In cloud speak, edge computing)
The difference here is that the system needs a lot of computing power. Luckily the environment is already clean and stable, so in this case, we went for server hardware. Server suppliers provide a large selection of different specifications with components that are designed for long life at 24/7 operations.
In this case, because the systems run without interaction and 24/7 we are deploying Linux to run on these systems. Linux ensures no uncontrolled reboots, and there are a large number of tools to manage these systems remotely, which aids the operations as time moves forward.
The Hybrid
Of course there are also hybrid approaches. In our case study from Kingston University in London, we needed both the reliability of measurements with the convenience of a LabVIEW user interface, so we had both the embedded system with a Windows interface.
Decisions, Decisions
These mini case studies have many of the same decision points that we always have to consider:
- Environment
- Operating Mode
- Computing Power and Peripherals
So how does your setup compare?