|I am building up a computer to control a programming test fixture that needs to program 20 devices simultaneously. |
I built a previous gang programmer and used a 24-port USB Hub (https://www.amazon.com/Manhattan-Port-USB-Hub-161718/dp/B0074024XU) to connect to the devices, and then connected the hub to the computer. The programmer did run OK, but I'm not convinced that it was going as fast as it could. I also noticed issues with enumerating 20 COM ports on the computer, depending on whether I was using a Desktop or Laptop machine.
Now I'm designing a new fixture and I'm wondering if it would be better to install four 5-port USB cards (like this one: http://www.newegg.com/Product/Produ... directly into the computer and have 20 cables running to the fixture, vs. using a single hub (or multiple smaller hubs). Has anyone ever had experience with this? THe data transfer rate of each device is low (11.5 kbaud serial comm), but it will be programming in parallel, so I want to make sure that whatever approach actually allows full bandwidth transfers for all 20 units.
What do you think?