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Asserting a stuck RTS Output (getting rid of "Flow Off: 1, Flow Control: Stop")?

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  • Asserting a stuck RTS Output (getting rid of "Flow Off: 1, Flow Control: Stop")?

    Hello! Are there any information on how to Assert a stuck RTS Output again from the code? Perhaps it's really obvious, but I can't get ahold of this.

    We haven't had the problem of RTS Output getting stuck in "Flow Off: 1" and "Flow Control: Stop" before in v1.4.0.0.R28, however it happens quite often in v1.5.0.0.R28. It seems that whenever RTS Output is asserted 2 times instead of 1, it stops responding and never times out. Usually it happens either immediately after hard boot or after some time of usage, and this condition is rectified only by doing a software reboot (for some time). Screenshot:

    We use Line 1 for forwarding data from UDP to serial and visa-versa at 921600 baud, 1 stop bit, no parity, and Hardware Flow Control enabled, and we use configurable pins CP1 (Line 2 Flow.CTS; Assert: Low; Weak Pullup) and CP2 (Line 2 Flow.RTS; Assert Low; Weak Pullup) whenever we need to setup the module or get settings using CLI from the external MCU.

    In the documentation, I found only DSR (ltrx_line_get_dsr) and DTR (ltrx_line_set_dtr) functions.

    Perhaps there is something with the pin states that must be accounted for?

    Any input, however insignificant, would be greatly appreciated !

  • #2
    It seems that something was spamming on the line. I was using the function bytes_available = ltrx_line_read_bytes_available() but there seemed to be a mismatch of bytes available, or 0 most of the time, so it did not get to ltrx_line_read. When I uncommented ltrx_line_read_bytes_available and just did ltrx_line_read with a large maximum number of bytes, I started getting data.

    I added an additional ltrx_line_purge to keep the queued byte buffer from getting monstrously large in case there is a lot of spam coming from Line 1.
    Last edited by ed4096; 09-19-2017, 11:25 AM. Reason: More info