[aprssig] usb - serial

[Jim WU3V]

Ben is this a laptop or a console based computer?
If the latter I have a computer I built up from parts and added 2 netmos 
serial modules(PCI)
for a total of 4 ports;they work extremely well I have a trimble gps clock 
(monitoring) and aprs Igate along with a PTC2 for a hf rms server.
I am quite happy with them.

Jim wu3v

----- Original Message ----- 
From: "Ben Lindner-VK5JFK" <vk5jfk at activ8.net.au>
To: "TAPR APRS Mailing List" <aprssig at tapr.org>
Sent: Saturday, May 01, 2010 23:46
Subject: Re: [aprssig] usb - serial


> Thanks for that Wes.
>
> Im not actually connecting a TNC at this stage. Its just connecting a 
> Davis Wx station to a computer without any serial ports and wanted to see 
> if people have had any issues with a usb-serial  setup
>
> cheers
> Ben
> VK5JFK
>
> Wes Johnston, AI4PX wrote:
>> The only problems I've heard of with usb serial adapters are on the 
>> transmit side of things.  Many prolific usb adapters won't send a packet 
>> out until they see a CR or LF... of course when you are in KISS mode, the 
>> packets terminate with $c0, so they usually end up getting sent when the 
>> next packets comes along, so they stay one packet behind.  The reason for 
>> this I think is that the packet _data_ actually ends with CR, but the 
>> packet _frame_ ends with $c0... so the serial adapter sends the packet 
>> out when it sees the CR, but that's not enough to make the TNC transmit 
>> since the KISS protocol is awaiting for the $c0 that denotes the end of 
>> the frame.  So the TNC is essentially sitting on go, waiting for that 
>> next $c0 to come along.  When the next frame is sent, the data portion of 
>> the packet once again ends in CR, the usb serial adapter sends it, and in 
>> doing so, the TNC finally gets to see the $c0 it needs to go ahead and TX 
>> the previous packet.  Hope this makes sense.
>>
>> In normal CONVerse TNC mode this isn't a problem since each packet ends 
>> with a CR and/or LF.
>> I'm not aware of any receiving problems with USB adapters though.
>>
>> Wes
>> ---
>> God help those who do not help themselves.
>>
>>
>> On Sat, May 1, 2010 at 17:54, Ben Lindner-VK5JFK <vk5jfk at activ8.net.au 
>> <mailto:vk5jfk at activ8.net.au>> wrote:
>>
>>     Hi All,
>>
>>     Is anyone using a Vantage Pro2 serial unit with the APRS data
>>     logger ( different to standard data logger ) with a USB-Serial cable.
>>
>>     If so, have you encountered any problems
>>
>>     cheers
>>     Ben
>>     VK5JFK
>>
>>
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