Mr. Beck, why have you now added a Raspberry Pi device to the range?
Beck: Initially, we just wanted to round off the edge gateway product portfolio at the lower end and offer something for the 'small purse'. However, none of our netX industrial network controllers were powerful enough at the time to handle the necessary software on their own. In our search for a suitable additional host controller, we received an offer from the Raspberry manufacturer Farnell-Elektronik to implement any customer-specific design with the Raspberry Pi 3 circuit - a new device platform was born! So we ported our Edge Gateway software to the device, but didn't publicize what was really working 'under the hood' of the device. We changed this when we equipped the same device with completely different software and subsequently sold it as netPI, the industrial Raspberry as an open ecosystem for edge connectivity. So in a real sense, we didn't actually add a new Raspberry device to the range, we just used the same platform with different software.

The netPI is equipped with Industrial Ethernet. So is there a customized Raspberry Pi in the housing?
Beck: Yes, there is: We wanted to equip the device with one of our netX industrial network controllers in any case, but at the same time wanted to remain flexible in relation to the netX. Farnell therefore did not design the netX in directly, but as a solder-on netX chip carrier module in stamp format. This means that other device variants can be created by reassembling the module without having to redesign it.

Other device variants?
Beck: The high demand for a pure industrial Raspberry without an industrial network connection led us to initiate further device variants at Farnell that no longer contain netX chip carrier modules: The product called 'netPI Core 3' will be launched in March; others with an integrated netX90 will follow.

How many similarities are there between your Yocto Linux and a Raspbian Linux?
Beck: Linux in the substructure consists first of all of a kernel. Only the version counts here. So if a Linux built under Yocto and the Raspbian Linux have the same kernel version, they provide identical functionality for the user. We, as well as the current Raspbian, use kernel 4.9. The applications are located above the kernel. In the case of Raspbian, the Raspberry organization determines which applications are included in the delivery; in the case of our Yocto-Linux, we do. And here there is essentially only one application that we pre-install, namely Docker. The beauty of Docker is that any application can be containerized and 'docked' to the Linux kernel as a container. Raspbian, for example, is available as a ready-made container. If you load this into the netPI, the Raspbian runs on top of our Yocto Linux. In the end, there is no difference for the user whether he uses Raspbian natively or containerized under Yocto.

They do not allow root rights or ssh access. So how does the software get onto the device?
Beck: We want to be as open as the Raspberry, but secure at the same time! That's why we don't allow anyone to make changes to the kernel or the system partition. The software signature is checked as soon as the device boots up to ensure authenticity. System updates or software components can only be installed if they have been signed by us. We have also integrated the AppArmor software into the Linux. It additionally monitors the rights of each of our applications. We have compiled Docker itself in a special variant so that some services cannot be used. The user imports the containers into the system via a web user interface. Here we have opted for the Docker management tool portainer.io. It can be used to click together the Docker services.

Do you offer Docker containers with specific application software?
Beck: For many people, container technology is still new and requires explanation. That's why we offer a large number of container examples. They are distributed via the 'Docker Hub' web page belonging to Docker under the 'hilschernetpi' repository.

We offer containers with bare Raspbian, Codesys, MQTT-Broker, Bluetooth, Node-RED and many more. We ourselves have a container in the program that turns the device into an IPC, including use of the HDMI port with mouse and keyboard. NetPI also encourages you to make your own containers public. IBM, for example, has already decided to put the Informix database in a netPI container.

Why is the Raspberry Gateway distributed via Amazon?
Beck: With netPI, it is the user who completes the device into a usable whole. Other Hilscher products claim to be ready-to-use. This break was the primary reason for us to sell netPI via Amazon. The second reason is the targeted clientele of the maker scene - only Amazon enables this clientele to purchase the netPI without barriers. Of course, the aim is not to sell all netPIs via Amazon - especially when it comes to larger quantities. This is where Hilscher distribution comes into play. The advantage is that OEM customers can also determine the characteristics of the device - such as the size of the SD card or the software configuration. We see distribution via Amazon more as a kind of 'teaser'!