[WriteLog] W5XD Keyer & USB connection

[W. Wright, W5XD]

Steve,
I have only tested the keyer with one particular model (from Belkin)
and got sub-par results. The problem was the speed of the transfers
from the PC onto the keyer. The transfers work, but a little sluggishly. 
You don't notice in the on-the-air CW--that comes out fine. Its when
you switch between radios or change CW speed, for example. It takes
a noticeable fraction of a second for the keyer to respond.

There may be newer USB/COM port adapters that have less delay. 
I am hoping that maybe someone else on the reflector can name one
that works faster.

On the other hand, the rig control from WL through through the port
works just fine.

The problem is that some USB/serial devices have long delays
in the driver (or hardware) between the PC and the RTS/CTS/DTR/DSR 
lines which are used to transfer commands to the keyer. This problem 
has never come up with motherboard or PCI or ISA COM ports.

By the way, in order for a human to notice the sluggishness, the delay
in the interface has to be up above 20msec or so. Compare that number
with data rates that even the oldest USB interfaces move, its 
almost unbelieveable that any designer managed to build a USB device 
that can change state at the equivalent of less than 50 bits per second. 
One keyer user tested an older model device that was so slow that 
the lights on an RS-232 break out box made a slow-moving display.
The protocol between WL and the keyer transfers the commands
accurately independent of the transfer speed, but such a slow transfer
made that adapter useless--it took several seconds from keyboard
entry to keyer response.

Wayne, W5XD

> -----Original Message-----
> From: writelog-bounces at contesting.com
> [mailto:writelog-bounces at contesting.com]On Behalf Of GW4BLE
> Sent: Tuesday, November 25, 2003 21:13
> To: writelog at contesting.com
> Subject: [WriteLog] W5XD Keyer & USB connection
> 
> 
> 
> Considering change of computer here, and with the lack of 
> serial ports on
> the current breed of machines I just wonder how (if?) the W5XD SO2R
> Keyer/Controller, (and Writelog generally), will perform if 
> it's configured
> with serial to USB convertors?
> 
> Is it just a simple matter of buying a USB-to-serial 
> convertor and instant
> plug'n'play under 'XP, or are there likely to be problems....
> 
> If you can advise - please reply direct to the reflector as I 
> am sure there
> are others in a similar position.
> 
> 73  es thanks
> 
> 
> Steve
> GW4BLE
> 
> 
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