On 06/05/2015 01:18 AM, Alexander Rössler wrote: > > Rafael writes: > >> On 06/04/2015 07:13 AM, Ron Bean wrote: >>>> If you need one computer to see the GUI and one for realtime >>>> effects, why not just start out with a real computer and load Linux and >>>> LinuxCNC on it? >> .... snip
>> In my HW support experience I came across PDP-11 systems running in >> steel mills, nuclear and hydro power plants, factories, etc. with little >> or no graphics. Most used VT100, some used more advanced color >> terminals. Systems with 32kW(ord) or 64kW RAM controlled huge machinery >> with RTOS on much slower CPU than we have today. > The future are distributed systems. Distributed setups are industrial > standard and are used everywhere from automotive to automation > industry. CAN and Ethernet are used these days to distribute neither one is suitable for strict real time. > functionality across different ECUs. The BBB is fine when it comes to > CAN but an even stronger platform from TI is coming up: the BeagleBoard > X15 with Gigabit Ethernet support Don't mix computer BUS and cabling. Two different things. Some cables do act as traditional extend bus but none at the length of an airplane or HMMVE. What good is Gigabit Ethernet when you need to connect a keypad, a switch, accelerometer, or optical sensor to BBB? Ethernet is not a bus, it's one of communications peripherals. > On the other edge of the spectrum we have another low cost solution that > is currently funded on kickstarter C.H.I.P. a 9$ dollar Linux computer > with Bluetooth and WLAN => a cheap solution to connect sensors. This is one of a kind toys that don't make a standard! Nor would anybody serious use it for a CNC machine. > I even heard about things like fly-by-wireless. Which boils down to > removing the wired buses inside a plane. So face the facts: Big > monolithic computer setups will soon be banned to server farms. Most airplanes and modern military vehicles use computers based on decades of developments on VME bus and it's derivatives because they need a lot of connections. That likely includes CompactPCI, it's emerging CompactPCI Serial, and VPX. As tiny lasers are getting cheaper, cost of building optical bus and compatible peripherals will become more common in the near future so we'll see even more data buses. Every computer in existence has a bus, available or not, for connections to additional peripherals. There is a bus on BBB, RaspberryPi, Radxa, and other little SBCs to add peripherals. My comment was about the problem with every little SBC having different connectors and their positions on the board while all are using "sandwich mechanical architecture" that cannot be expanded easily. Based on what I've seen at Embedded computers trade show this year I can easily say that "computer data bus" won't go away any time soon. PCIe, VME, VPX, CompactPCI, PC104 and on and on. Companies are clearly commiting to support for advanced buses for the next 20 years or more. >>> and a PCI slot for a GPU. Another solution might be something like a BBB >>> that plugs into a PCI slot in a generic PC. Either one eliminates the >>> USB connection, which is the real problem. >> >> Good idea assuming there would be a volume to keep the costs down. >> >> IMO it would be better if ARM architecture based universal bus would >> emerge for use in small embedded systems under $100 so that vendors >> would be encouraged to build controllers with "Mesa card" like >> functionality and other interfaces to handle digital and analog IO >> connections. >> >> This thread brought up interesting ideas and comments; good starting >> point for a "kickstart" project ;-) > -- Rafael ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
