USB-8506 LIN module

[Sarra22]

Hello,

I would like to know if the USB-8506 LIN module (two ports) really works in parallel mode.

I have two DUTs and I’m using LabVIEW with two VIs running in parallel, each one using a different port. However, in practice it does not seem truly parallel. When I send a COMMAND to the first DUT, the second one does not work at the same time. It looks like the transmissions are sequential rather than simultaneous.

Has anyone experienced this behavior?
Does the USB-8506 support true parallel communication on both LIN ports, or is there an internal limitation?

Thank you.

[ZYOng]

What type of XNET sessions are you using?

There is only one USB cable. Those two VIs need to take turns to communicate with individual ports over a single USB path.

[Sebastian.Weber]

Can you show your code?

Here, I open one session per port of this module, and try to read a frame with 2s timeout. Since nothing is connected, I even have to configure to start without bus power. This is intended, because i WANT the read-frame-VIs to run for 2s.

Running one after the other takes 4s, running both in parallel takes 2s. So yes, those VIs run in parallel.

Are your XNET functions inside a subVI, which is called twice? A subVI cannot run twice in parallel unless it's reentrant.

Contrary to the other answer, USB cannot be an issue, here. Lin is max. 20kBit/s, while even the ancient USB1.0 supports a minimum of  1500kBit/s.