somenax.blogg.se - Checksum error serial port

We have successfully tested the USB hubs by EXSYS (-> ).

The hub should be avoided then or replaced by a hub of a different supplier. If the communication does not fail anymore then, it is very likely that the hub has been the root cause. > Our initial hint is always to use a direct USB line (without a hub) in between the PC and controller.

USB hubs are often a root cause of USB communication problems (based on different support cases). > Is the problem solved in case the USB cable is kept away and not be parallel to motor power cables or motor cables are shielded and tied to Earth?Ĭross reference: How to connect a cable's shielding to Earth potential?

USB cable close to motor power cables (or wires of other inductive loads).

> Is the problem solved in case an USB cable of a different supplier is in use? > Is the problem solved in case a shorter cable is installed (at least for testing)? Possible root causes and chance for improvements: If there is an EMI issues present, USB is quite often the interface which reports communication errors before any other bus types are even affected at all.

) it gets more important to take care of high quality USB cables, reliable industry-proven USB hubs, and measures to reduce possible EMI impact. Based on the often higher risk of signal disturbance (EMI) within industrial environments (due to motors, relays, power connectors. Nevertheless USB is partly in use by industrial systems too. USB interfaces had been originally intended and designed for office applications and devices. USB is generally spoken one of the interface with the highest sensitivity concerning external signal disturbance (so-called "EMI = Electromagnetic interference").

What can be possible root causes in case of sporadic USB errors reported by the controller or software?.