3 ms·
> Camera Link, another serial protocol, also just works. USB is also a serial protocol on the wire ;-) But there are so many layer of complexity on the top tha
by ale42 4y ago
> Camera Link, another serial protocol, also just works.
USB is also a serial protocol on the wire ;-) But there are so many layer of complexity on the top that make it indeed a nightmare in many situation.
I worked with a control system using USB, where the connection to the controller had to last for weeks. Regularly, the device stopped working (usually entirely disappearing from the device list) and I had to add support on the software to transparently allow the device to return (and people had to unplug and replug the board when receiving the "device disappeared" alert). Same stuff on RS-232 just worked without a single issue...
- bmitc 4y agoI understand USB is a serial protocol, but it's the worst I have ever used. (Was just clarifying for Camera Link.) Your example is exactly the type of stuff I had in mind. We had the same issue with a camera. We also wanted to power cycle part of the system, since the camera was water cooled to turn it off, but this was basically impossible with the USB communication without farming out the camera communication to an entire other OS process/program such that the communication could be restarted. That manufacturer, for whatever reason, only implemented streaming the images over Camera Link but didn't implement their settings over Camera Link. And I swear to god, another USB camera in the same system wouldn't work through a hub and only worked reliably when directly attached to a specific USB port on the computer. Mindblowingly frustrating.