I have designed a double controller enclosure to combine two controllers into one enclosure. The I/O terminal blocks are all on the same plane and the Network interfaces are on opposite faces of the enclosure. It is important to visualize that the orientation of these interfaces is the result of installing the master boards in opposite directions. In other words, if we name the 4 sides of the enclosure in clockwise order, A,B,C,D and the bottom E and top, F, I have the terminal blocks on E. Controller-1 board is oriented such that it’s network interfaces are on side A which places its heat sink toward side D. Controller-2 is oriented opposite with its network interfaces on side C, which places its heat sink toward side B.
Now that we have established that the heat sinks are on opposite sides with the Controller-1 having its heat sink toward side-D and Controller-2 having its heat sink on the opposite side-B, I can say that the fans and energy eaters are both on side-D. This means that the fans on side-D are close to Controller-1 heat sink and far from Controller-2 heat sink.
This configuration has resulted in Controller-2 kicking the Controller-2 fan into high speed after 30 minutes of turning on the robot. If I issue a Polyscope get_controller_temp() command it actually shows that Controller-2 is running 5 degrees cooler than Controller-1 that is running at 35C. Still, Controller-2 kicks the fan into high speed.
Finally, my questions, does the RTDE command float masterBoardTemperature actually give the chipset under the heat sinks temperature and is that different from the temperature returned by the Polyscope get_controller_temp() temperature?
Then, assuming the chipset temperature is different than the controller temperature, what is the safe limit for the chipset and is there a safety shutdown high limit and what is that limit?
Also, is there a way to command the fan to go to high speed before the temperature of the chipset demands high speed. I would like to command Controller-1’s fan to kick to high speed to help Controller-2 to get more air because it’s heat sink is farther away.
We have placed an auxiliary fan into the cabinet when combining a UR controller with 4 motion controllers, this helped the system evacuate the heat from the cabinet and keep the controller cool without having to run the fan on high speed. We made this a draw fan versus a forced fan to draw air through the cabinet in addition to the UR forcing air in. The UR was at the bottom of the cabinet and the other motion controllers were above it with the draw fan at the very top.
You will not be able to control the fan. The source of that temperature reading is the same one that the controller will shut down via so that is unfortunately as much as we can share. The e-series control box will shut down at 70C. I would follow Matt Bush’s advice and add another fan to stir the air continuously.