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How to test RTS and CTS only RRS feed

  • Question

  • Hi,

    Our Hardware has RTS and CTS. Does any of the CETK tests specifically these two.

    I don't have any other control signals such as DTR, DSR and etc...

    Basically It has Tx, Rx, RTS, CTS and GND.

    Regards,

    GSR

    Monday, October 17, 2011 11:34 AM

All replies

  • You can use the pserial.dll of the CETK. There are versions for your target and your PC. The command line looks like this.

    tux -o -d pserial.dll -c" -p COMX: -m" (master)

    tux -o -d pserial.dll -c" -p COMX: -s" (slave)

    I think test 13 tests hardware flow control including DSR/DTR but at least you would get also information about the results of CTS/RTS. Without the DSR/DTR lines the test will report a skip I think.

    Best regards,

    Mike

    Monday, October 17, 2011 11:56 AM
  • Hi Mike,

    Thank You for the information.

    One question the existing MDD code in WinCE implements the old RTS/CTS handshaking?

    I was referring old w.r.t. the information given in the following URL http://en.wikipedia.org/wiki/RS-232 (RTS/CTS handshaking)

    Regards,

    GSR

    Thursday, November 24, 2011 11:31 AM
  • Yes the MDD implements it: you can enable it setting the appropriate members of the DCB structure for the SetCommState.

    If you want to 'manually' test RTS and CTS you can short them and use EscapeCommFunction to set/clear the RTS signal and GetCommModemStatus to check the CTS signal level


    Luca Calligaris lucaDOTcalligarisATeurotechDOTcom www.eurotech.com Check my blog: http://lcalligaris.wordpress.com
    Thursday, November 24, 2011 1:17 PM
  • I don't know if the MDD implementation refers to the description in your link.

    I only know that the implementation in the UART driver is a software handshaking. That means that the driver handles the RTS line by changing the level of that signal through the UART controller. Some UARTs are also offering hardware flow control where the UART handles all the handshaking

    Is that what you are asking for?

    Best regards,

    Mike


    Digi International Inc http://www.digi.com
    Thursday, November 24, 2011 2:17 PM
  • Hi Luca Calligaris and Mike,

    Thank You for the replies and your time.

    If I have to use the following way In older versions of the specification, RS-232's use of the RTS and CTS lines is asymmetric: The DTE asserts RTS to indicate a desire to transmit to the DCE, and the DCE asserts CTS in response to grant permission. This allows for half-duplex modems that disable their transmitters when not required, and must transmit a synchronization preamble to the receiver when they are re-enabled, then I have to use the RTS_CONTROL_TOGGLE 

    If I have to achieve A non-standard symmetric alternative, commonly called "RTS/CTS handshaking," was developed by various equipment manufacturers. In this scheme, CTS is no longer a response to RTS; instead, CTS indicates permission from the DCE for the DTE to send data to the DCE, and RTS indicates permission from the DTE for the DCE to send data to the DTE. RTS and CTS are controlled by the DTE and DCE respectively, each independent of the other, then I have to use RTS_CONTROL_HANDSHAKE.

    The above description was retrieved from  http://en.wikipedia.org/wiki/RS-232

    Is this correct?

    Regards,

    GSR

     

    Friday, November 25, 2011 5:25 AM
  • Hi,

    the second description is correct. With the first description I am not 100% sure but it also make sense to me.

    Best regards,

    Mike


    Digi International Inc http://www.digi.com
    Friday, November 25, 2011 10:25 AM