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As a device builder creating those machines (well, industrial CNCs, but similar idea) I don't have many options when trying to build something with a useful lif

As a device builder creating those machines (well, industrial CNCs, but similar idea) I don't have many options when trying to build something with a useful life of 20+ years. I just received an order for another machine in a lineup that started with some using Heidenhain controls from the early 90s, we ripped out those controllers and replaced them with models running a custom black box RTOS based on Motorola DSP 56002 chips on ISA cards that were on Windows 98 and Windows XP motherboards, then that company got aquihired and they stopped making those cards, there was a brief foray into PowerPC and now we're installing Arm processors running surprisingly modern Linux 4.9 with preempt_rt. We're talking to these motion controllers using VB6 running on a bunch of Windows 7 PCs with a few compatibility hacks enabled, and I'm installing new fanless PCs with Windows 10 LTSC 21H2, which claims support until 2032-01-13. If it's not running those relatively public, well-documented systems, it's likely a PLC or robot containing a proprietary ASIC running some WindRiver RTOS, and completely subject to the whims and survivability of that product line. I love my customer's maintenance department, they're unusually thorough and attentive to preventative maintenance, greasing and oiling and replacing wear items, root-causing failures and keeping the machines in good working order for decades. But when you keep fixing each individual small part that breaks, eventually the market moves on and you have to throw all the replaceable parts away and start over. The process requirements haven't changed, the weldments and castings aren't broken, it's just that you can't replace a failed servo drive or Core 2 motherboard or ISA card because the supply chain gave up on them 10 years ago. There's no great advantage of Windows 10 LTSC and a 64-bit Arm controller over Windows 98 with 56002 ISA cards except that I can buy the former today and I can't buy the latter because no one makes them anymore. There is no control OS or hardware supply chain that lasts as long as military, industrial, or scientific equipment can be made to last. Fanuc and others try with massive vertical integration and a "never deprecate anything" mantra, but they don't run their own semiconductor fabs to guarantee production of chips for stuff that doesn't keep up with the rat race. Yes, I'll keep supporting my company's gear for as long as possible, but sometimes the answer is that I need to throw away 4 working servomotors, drives, a controller, and a PC, and invest 600 engineering hours into making this machine do the exact same thing it did last week, because that 5th drive blew the IGBT and took out the controller and no one can get a replacement. Customers don't like to issue $100k invoices when a $1k subcomponent dies...because that $1k quote was from 2008, and it's now literally priceless.

whizzter 4y ago
Any reason communication with these kinds of machines hasn't been built on top of something like CAN or Ethernet?
- LeifCarrotson 4y ago
  It is, we're now installing CiA 402 or "CAN in Automation CANopen Drives and Motion" servos (which didn't exist at the time the first ones were built) running on an EtherCAT real-time protocol stack. That will hopefully make replacing servos in the future relatively seamless. Unfortunately, though, just using a CAN or Ethernet physical layer doesn't solve the problem of the https://xkcd.com/927/ https://xkcd.com/927/ standards proliferation of industrial protocols: Some customers require CIP motion over Ethernet/IP (a dog-slow Rockwell proprietary protocol), there's old MACRO fiber optic rings, Sercos III (and prior serial protocols), a dozen high-speed serial standards for communicating with absolute encoders, and, of course, good old-fashioned hardwired digital I/O - which might be either analog velocity/torque or step and direction, RS422 differential or single-ended, etc. etc. etc. You'd hope that you could just plug something that spoke CAN or Ethernet into something else that has the same physical interface, and the two would work together. Sometimes, you get lucky and that works out. But the ever-forward march of industry leaves behind a graveyard of yesteryear's abandoned products and protocols.
jiggawatts 4y ago
The trick is to make the controller board swappable and an independent set of products. E.g.: If you make 30 different kinds of industrial machines, have one controller board as an additional product for a total of 31 SKUs. When the controller board is too old and no longer supported, make a new SKU that is backwards compatible with the old machines. E.g.: Some televisions allowed the entire controller board to be swapped out, upgrading the TV's OS and HDMI ports with new capabilities. The panel and the case stayed the same. Similarly, a CNC router or whatever is "just" some analogue wires that go into a digital board. Make the digital board swappable. A similar mistake that I see is customers that are used to "archive grade paper" asking me how long digital backup tapes last. That's the wrong question!. The important thing is to be able to copy from old tapes to new tapes with full fidelity, which digital technology enables, but analogue technology does not. You can retain data indefinitely with digital media that lasts just a few years. Instead of trying to scrounge up some old floppy or CD readers, just copy the data to BluRay, then cloud storage, and then... whatever.

whizzter 4y ago

Any reason communication with these kinds of machines hasn't been built on top of something like CAN or Ethernet?

LeifCarrotson 4y ago
It is, we're now installing CiA 402 or "CAN in Automation CANopen Drives and Motion" servos (which didn't exist at the time the first ones were built) running on an EtherCAT real-time protocol stack. That will hopefully make replacing servos in the future relatively seamless. Unfortunately, though, just using a CAN or Ethernet physical layer doesn't solve the problem of the https://xkcd.com/927/ https://xkcd.com/927/ standards proliferation of industrial protocols: Some customers require CIP motion over Ethernet/IP (a dog-slow Rockwell proprietary protocol), there's old MACRO fiber optic rings, Sercos III (and prior serial protocols), a dozen high-speed serial standards for communicating with absolute encoders, and, of course, good old-fashioned hardwired digital I/O - which might be either analog velocity/torque or step and direction, RS422 differential or single-ended, etc. etc. etc. You'd hope that you could just plug something that spoke CAN or Ethernet into something else that has the same physical interface, and the two would work together. Sometimes, you get lucky and that works out. But the ever-forward march of industry leaves behind a graveyard of yesteryear's abandoned products and protocols.

jiggawatts 4y ago

The trick is to make the controller board swappable and an independent set of products. E.g.: If you make 30 different kinds of industrial machines, have one controller board as an additional product for a total of 31 SKUs. When the controller board is too old and no longer supported, make a new SKU that is backwards compatible with the old machines. E.g.: Some televisions allowed the entire controller board to be swapped out, upgrading the TV's OS and HDMI ports with new capabilities. The panel and the case stayed the same. Similarly, a CNC router or whatever is "just" some analogue wires that go into a digital board. Make the digital board swappable. A similar mistake that I see is customers that are used to "archive grade paper" asking me how long digital backup tapes last. That's the wrong question!. The important thing is to be able to copy from old tapes to new tapes with full fidelity, which digital technology enables, but analogue technology does not. You can retain data indefinitely with digital media that lasts just a few years. Instead of trying to scrounge up some old floppy or CD readers, just copy the data to BluRay, then cloud storage, and then... whatever.