I ran into this problem with the Entrega 4-port USB serial device back when
beta testing the W5XD+ keyer. The problem is that the keyer protocol is
implemented by switching several RS-232 signals on and off. I can't remember
which ones, but probably RTS, CTS, DTR and the like. Wayne and I found that
these signals switch very, very slowly on a USB serial port compared with a
standard RS-232 UART-based port, and this affects the keyer protocol
throughput so much that the interface was useless. I complained about the
slow switching speed to Entrega, but got no response (they disappeared and
were acquired by Intel, which has since dropped the product.)
It's interesting that this is not just an Entrega problem. This is the first
report I've heard of it on a non-Entrega device. Is anyone using the W5XD+
keyer successfully on a different brand USB serial port?
I had thought that Entrega didn't bother to fix the problem because normally
the switching speed of the RS-232 signals is relatively unimportant
(although it could be a factor for hardware flow control at high data
rates.) But perhaps this is an inherent problem with USB serial ports.
That's hard to believe -- I can't think of any reason why RS-232 signal
switching on USB serial ports should be so slow. It's true that, unlike a
UART-based port, the device is translating a serial stream of commands from
the device driver into high and low voltage states on the pins, but if it
can do that on the Send Data and Receive Data pins (2 & 3) fast enough for
156K baud, then it ought to be able to flip the other signals just as fast.
73, Dick WC1M
> -----Original Message-----
> From: Keith Regli [mailto:keith@kregli.com]
> Sent: Monday, February 03, 2003 6:25 PM
> To: writelog@contesting.com
> Subject: RE: [WriteLog] W5XDMulti+ Keyer and USB serial
>
>
> I see a similar behavior on the Entrega/PortGear device. Wayne posted a
> note a few months ago mentioning the behavior, so I'm guessing it's
> somewhere on his list to try and figure out why it happens.
>
> Keith Regli (K7KAR)
> mailto:keith@kregli.com
> http://www.kregli.com
>
> -----Original Message-----
> ...
> When I move the W5XD keyer to the USB port (com5) I do get rig control
> for
> the FT1000mp OK. But now I get a very strange behavior. It takes about 4
>
> seconds to switch focus from one radio to the other !!! When you click
> on a
> call, the call enters instantaneously but 4 seconds later the focus
> switches to that entry window (so I guess any transmission would go to
> the
> wrong radio). In further investigation, this has to do with CW generated
> by
> W5XD multi+. CW, PC generated does not cause the delay in focus
> switching.
>
> Is any one else using the W5XD multi+ keyer on a USB serial port? And
> if
> so what type of USB serial device. This is the first thing that seems
> not
> to work on the RocketPort in this computer.
> ...
>
>
>
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