Automated signal logging applications with Red Pitaya
- Posted by Red Pitaya Team
T&M is an activity that is usually associated with clean and protected environments, such as electronics laboratories, study rooms, and even basements. These are the traditional homes for generally delicate tools and instruments, where electronic engineers, students, and hobbyists have been enjoying the versatility of Red Pitaya units ever since they were launched. It is precisely this versatility that makes these units the perfect tool for signal logging, with the added benefit of their small size. With the STEMlab 125´s credit card dimensions making it ideal to carry around, it´s easy to imagine how this also makes it extremely well suited for portable monitoring, where size is important for the engineer to move around in the field, transporting this all-in-one remote lab with only minimal effort.
But size is not everything, and not all applications can be performed in a sheltered environment. This is what makes the new SIGNALlab 250-12 so well adapted for industrial applications. Performing at twice the sampling speed as the STEMlab models in an operating temperature range between 0 and 55°C, the standard delivery kit of this new instrument comes with a ruggedized protection case, making it an excellent choice for field engineers, since it is small and light enough to fit in a briefcase and be installed in the most inaccessible spots.
Signal logging in the field often involves dragging around several instruments and complicated setups in conditions which are far from ideal. The flexibility of the SIGNALlab allows the entire setup to be done in the lab, configuring input parameters, data storage or data communications, and so on, using one of the numerous, standardized tools such as LabVIEW or Matlab, or even customized software. Afterwards, once the unit is installed in the field, the only thing left to do is connect the power supply, the sensors to one or both BNC inputs, and the Ethernet cable for wired communication, if required, and then fire up the instrument for its long-term signal logging task. From then on, everything can be handled and monitored remotely, allowing the engineer to save valuable time and money and even to intervene in the setup if necessary, in the case of unforeseen events. In terms of cost savings such a system is definitely an important asset, since it avoids unnecessary additional trips to the field.
A traditional long-term logging application is the monitoring of environmental parameters. Today we are in a time when climate change studies are becoming increasingly more important, with the number of measurement points and units steadily on the rise. Fortunately, climate change is not happening at a rate where it is necessary to sample data at a 250 MHz frequency, so the standard sensors for this task are usually of a simpler and cheaper type. But with a high number of field sensors comes an increased possibility of failure. The ease of setup of the SIGNALlab 250-12 unit, as well as its remote-control feature, are among the many advantages of using it for debugging sensors in cases like these, in order to understand why they fail. And if the measurement hut is too far away to allow wired or wireless communication, data can simply be stored on an SD memory card for readout at a later date. The same strengths are also clear in civil engineering applications, where the behaviors of slowly evolving parameters need to be monitored, such as in projects like bridges, skyscrapers and other large-scale structures. In applications like this, automated signal logging is essential, because important events rarely occur when you’re watching. Alarm levels can thus be set to trigger whenever critical thresholds are reached.
However, not all applications show a slow evolution in their parameters, which is why the increased sampling rate does offer an important step forward in the development of new Red Pitaya units – in this case, the SIGNALlab 250-12. This is certainly the case for fast transients in power inverters. Since electric power generation no longer exclusively occurs in large power plants, but is more and more dependent on a multitude of smaller, delocalized units, such as windmills or solar panels, the collection of operation data has become more fragmented and geographically spread. All the previously mentioned benefits of Red Pitaya units, like in-house setup, simple installation and launching, are also important assets in these applications. Moreover, the intrinsic performance of the SIGNALlab unit is likely to be used to the fullest of its capacities. In power electronics, fast transient currents and voltages are always potential causes of equipment failure, which is why early detection and alarm triggering is essential. And when it comes to fast transient detection, obviously, a fast sampling rate is also critical. When sampling at 250 MHz, the data files will obviously be large, which is not a problem if they can be communicated fast enough to a central server. If this is not the case, another solution is to set the Red Pitaya to start collecting data only when a specific parameter threshold is reached, and then store it on the local memory.
Other applications where fast sampling is crucial are those related to RF communication. For example, a field engineer, debugging NFC devices at 13.56 MHz, where the 12-bit sampling at 250 MHz allows detailed signal analysis. Or their colleague, trying to detect EMI and RF noise preventing electronic circuits from functioning properly. In both cases, whether going from one NFC device to another or chasing possible parasitic signals, the operator will certainly welcome the relatively small size of the SIGNALlab.
The STEMlab 125 boards are already famous for their ease-of-use and small size, allowing OEMs to embed them in a straightforward manner. With its ruggedized protection case, the SIGNALlab 250-12 clearly demonstrates Red Pitaya’s ambition to widen its horizon and become a key player in industrial applications with harsher conditions. There is no lack of areas where this unit could become a gamechanger, and its technical performance and versatility, as well as Red Pitaya´s traditional adaptability to customer needs, are clear assets on the path towards this objective.