Given how little data CAT control needs to transport you could likely reduce things down to 4800bp/s and still more than exceed requirements, and those lower speeds reduce the risks of both buffer overflow and signal corruption. However, selecting high serial speeds (such as your initial 115,200bp/s) can lead to corruption of the bits (on the serial port side, not USB side) due to buffer overflow or signal corruption as the buffers are quite small and signal integrity is not great at high data speeds. I guarantee your USB ports are more than adequate to handle RS-232 serial port data as they will typically be operating at either 12Mb/s (USB 1.1) or 48Mb/s (USB 2.0) depending upon the connected device (typically the 12Mb/s speed for RS-232 devices), so handling the lowly kilobits of RS-232 is barely a strain even if you had a dozen of them. Why do i think it's the MBP? Because i tried a Late 2011 MBP running the same OS as my 2015 one (Sierra) this morning and that MBP doesn't have the issue.Īny idea what has changed in the USB handling between 20?Īny idea how i can manipulate the buffering if the USB port on the 2015 MBP? In the video you can also see that i am sending out a CW signal not using the MBP and that signal is clean. I tried this with various USB cables and various different programs and the behaviour is the same with all.

However, as you can see in the video, the audio is interrupted and gets worse over time up to the point that the USB port is not receiving any data anymore and the transmit signal gets interrupted. The effect should be that the radio sends out this continuous tone on the air. In this video i first put a continuous tone on the USB port. I am using a USB cable running at 115200 between my radio and the MBP.

I seem to have a problem where the USB ports are not able to handle the traffic going from my software to the radio.

I am a HAM and i am using my Early 2015 MBP for data communications. I guess i'd post it here as well, maybe someone can shine a light. This morning i posted the below message on the Apple forums.

Mac powerbook pro usb intermitten