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X220 with Native Serial
Posted: Wed Oct 05, 2011 12:57 pm
by crised
Hello,
Looking for Native Serial RS-232 for my W7x64 X220. Tired of the RS-232 to USB connector.
How this sounds?
http://intrl.startech.com/Cards-Adapter ... RT~EC1S952
Re: X220 with Native Serial
Posted: Wed Oct 05, 2011 2:29 pm
by dr_st
How is one converter (ExpressCard-to-RS232) more "native" than another converter (USB-to-RS232)?
$77 for this?
Re: X220 with Native Serial
Posted: Wed Oct 05, 2011 2:41 pm
by crised
because express card has more than 4 pins as USB does...
Re: X220 with Native Serial
Posted: Wed Oct 05, 2011 3:10 pm
by dr_st
That is true, but why is it important specifically for RS232 usage? I am seriously asking, as I am not familiar with RS232 intended usage so much.
Re: X220 with Native Serial
Posted: Wed Oct 05, 2011 4:49 pm
by bill bolton
crised wrote:How this sounds?
It has a hardware USART in it, and that is as good as it gets nowadays in terms of provisioning a
real serial port
Cheers,
Bill B.
Re: X220 with Native Serial
Posted: Wed Oct 05, 2011 4:54 pm
by automobus
A USB device shares the bus. Going through USB adds latency. Same story with MIDI and audio. Ask the experts who wrote MIDI on Wikipedia: "USB is over 15,000 times faster than MIDI, however, there is more latency introduced". Even USB 1 afforded the throughput for a 7-channel sound card. But even after the introduction of USB 2.0, professional external sound cards most often use IEEE 1394. Another thing to consider is drivers: a driver for serial USB device plus driver for USB host controller, adds potential for one more software failure.
Re: X220 with Native Serial
Posted: Thu Oct 06, 2011 3:28 pm
by crised
Why as real as it gets?
It has an UART... device that I have has UART too. so this is real serial, right?
Re: X220 with Native Serial
Posted: Sat Nov 12, 2011 11:02 am
by automobus
I found a person who reports a reason against USB serial adapters: their baud rate is not low enough.
http://www.aa8ia.org/2010/10/07/usb-to-serial-adapters/
Re: X220 with Native Serial
Posted: Sun Nov 13, 2011 4:46 pm
by bill bolton
automobus wrote:their baud rate is not low enough.
That's only an issue for RTTY purposes nowadays.
Most laptop users who are looking for
full RS-232-C capability, need their laptop to look like a hardwired
serial terminal to some other device, and will operate at much higher baud rates than RTTY applications.
Cheers,
Bill B.