RoadTest: RPI BC DIN rail housing for Raspberry Pi computers
Author: stgmavrick
Creation date:
Evaluation Type: Independent Products
Did you receive all parts the manufacturer stated would be included in the package?: True
What other parts do you consider comparable to this product?: No other similar products on the market.
What were the biggest problems encountered?:
Detailed Review:
Review of the Phoenix Contact RPI-BC
Introduction/Background
My name is Marshall. I’m a controls engineer/programmer. I’ve been in the PLC programming field for the last 11 years. I’ve worked with the majority of the more popular PLC systems including Allen Bradley, GE, Control Microsystems, Modicon, etc. As well as many HMI platforms. The majority of my work is project based in the chemical, water and wastewater fields. I’ve been lightly tinkering with the Raspberry Pi off and on over the last year or so with minor projects around the house. Being a PLC programmer and not too fluent on coding like python, c languages, and .NET I’ve yet to really dive into the GPIO programming aspect past simple on/off python scripts. My company designs and programs PLC/OIT enclosures. One thing I’ve been wanting to get into for years was a low cost OIT capable of monitoring various PLC linked processes. When I read the posting for the Phoenix Contact RPI housing I had to get into the program and give it a shot.
Initial impressions
If you’re familiar with the Phoenix Contact product lines the RPI-BC easily recognizable as a PC product. Like you’d expect the housing is well made, durable, and of the same materials as their terminal blocks, other housings, power supplies, and small controllers. So if you’re wondering if they skimped on the quality for the low cost housing; they didn’t. The housing itself assembles tightly and securely. You'll feel no slop or play in the RPI board when mounted and housed. For low processing use there appears to be adequate venting as I have not seen any thermal issues during use. There is adequate room for accessing some of the onboard ports such as the HDMI, 3.5mm, and micro USB port. However, there are some limitations to remainder of the I/O which I’ll get into shortly.
The Test Projects
The first test project I put the RPI-BC through was to use it as an OIT for a small pump control panel. Unfortunately the pictures of that enclosure have been irrecoverably lost due to an HDD crash and the panel is no longer in my possession; my apologies. The RPI-BC was mounted via DIN rail in a small stainless NEMA enclosure and powered by a 5V PS which was used to pump from a pit controlled by an Allen Bradley Micrologix 1400 PLC. This system was connected to a larger network and was monitored by an HMI system; Trihedral VTSCADA. One benefit of the VTSCADA system are the inclusion of web browser clients using HTML5 for full remote monitoring and control. Via the Chrome browser on the RPI and a panel mounted Monitor this was an easy task to get remote monitoring and control reliably and much more cost effective than a purpose built OIT such as an AB PanelView. However, I wanted to go a little further with the capabilities of the RPI and the RPI-BC housing.
The second project was something around the house. I have a simple Aerobic septic system with a simple on/off timer circuit. Not happy with the simplicity of it (Thank you engineering brain) the moment the timer failed I jumped at the chance to over engineer and complicate it. I wanted remote monitoring of On/Off status. This was actually a well needed addition as I’m still not sure how long the original timer was out of order. But, I figured while I’m in it I’d go ahead and use the RPI to control it, monitor power consumption, connect to the home wired Ethernet network, and eventually add more sensors and functionality than the original on/off timer system. One of which will be DO (Dissolved Oxygen) control to make the system more efficient, especially on energy consumption.
Unfortunately this has been proving difficult…
The components
This is the current status of the panel. I’ve not mounted the contactor nor completed the wiring as there will need to be some thought out modifications for mounting the RPICT3T1 board. (Ignore the ends of the DIN rail, it was scrap laying around!)
This is where there are some limitations to the PC RPI-BC housing. Accessing the GPIO header is not easily done unless using the front panel and creating your own PCB to fit within the front panel. If you plan on using boards/shields that mount directly to the RPI you will have fitment issues. The RPICT3T1 was not able to be mounted to the RPI due to the low form factor of the BC Housing. As per the picture you can see that a ribbon cable was used to route it outside of the housing. I have some ideas of remote mounting the 3.5mm CT jacks and checking clearance but it just arrived last week and it has put the project behind schedule of the review deadline. This project is still in the planning phases and will require more time. Expect a follow up project thread.
Thoughts/Conclusion
As an enclosure it does its job. As I mentioned it’s well built. I have no fears that it won’t hold up to panel use that it’s been designed for. I’d feel completely comfortable using it in customer panels and I plan on making use of it and the RPI for OIT purposes for projects in the immediate future with more control based use further down the road once development and testing has proved the RPI can handle some usually PLC controlled tasks.
However, there are some improvements that I’d like to see. Phoenix contact has a DIN rail bus adapter system that is compatible with the RPI-BC. I’d like to see a version of the RPI-BC that used the HBUS for power supplying the unit without having to use an external USB cable. This would simplify connections in an industrial control panel. I’d also like to see interchangeable faceplates for the housing’s openings. I would like to see a faceplate connecting the HDMI, 3.5mm jack, and the USB so those could be accessed externally. I would also like to see more/easier options for accessing the GPIO header as well as the display connector for projects where those are required. Accessing the SD slot is fine for a RPI 2B however if you were to use a RPI 3B it would require removing the RPI from the housing to access the SD card.
In conclusion, I’d like to deeply thank Element14 as well as Phoenix Contact for allowing me to test and review the housing. (And rscasny for allowing me to be late on my review. Sorry!)
