With C#, the serial port object gives you the ability to enable RTS checking or
disabling it. That is what I was refering to.
Kurt
On Sun, Oct 6, 2019, at 10:32 AM, Stephen Adolph wrote:
> Kurt,
> Maybe it is just me but I find your description a bit unclear.
> What do " enabled" "disabled" "active" mean?
> thanks-
>
>
>
> On Sun, Oct 6, 2019 at 10:47 AM Kurt McCullum <[email protected]> wrote:
>> __
>> Guys, I did some testing on my T200 to figure out the whole serial port
>> wiring issue.
>>
>> Test 1:
>> 1. Write a test application to open the serial port on the PC with DTR/DSR
>> and CTS/RTS disabled
>> 2. Go to TELCOM on the T200
>> 3. STAT 98N1ENN
>> 4. TERM
>> 5. Press any key on the T200 and it freezes.
>>
>> Test 1:
>> 1. Write a test application to open the serial port on the PC with CTS/RTS
>> disabled but DTR/DSR enabled
>> 2. Go to TELCOM on the T200
>> 3. STAT 98N1ENN
>> 4. TERM
>> 5. Press any key on the T200 and it freezes.
>>
>> Test 3:
>> 1. Write a test application to open the serial port on the PC with CTS/RTS
>> enabled but DTR/DSR disabled
>> 2. Go to TELCOM on the T200
>> 3. STAT 98N1ENN
>> 4. TERM
>> 5. Press any key on the T200 and all data is sent to the PC and sent back
>> to the T200. Works perfectly.
>>
>> I Then tested to see if TELCOM is actually using RST/CTS. For this I wrote a
>> small application to send a large file to the T200 with Xon/Xoff turned off.
>> I then put a bit of code in place to see if the RTS/CTS flags were ever
>> changed by the T200 to tell the PC to stop sending. What I found was that
>> the T200 never sent a flag to the PC signaling to pause sending data due to
>> the buffer being full. This caused garbage on the screen.
>>
>> So, what I can conclude from all of this is that the T200 serial port
>> hardware MUST have the RTS/CTS active or it will freeze the hardware. But
>> the TELCOM application does not use those signals to halt data transfer when
>> the buffer is full. Instead it relies on Xon/Xoff. Hope that clears things
>> up a bit on the mystery of the T200 serial port.
>>
>> Kurt
