Comments on: Noise sensitivity of USB-serial converters? http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/ Join the resistance. Wed, 08 Feb 2012 23:19:29 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Andrew http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-3352 Andrew Sun, 08 Mar 2009 00:22:00 +0000 http://mightyohm.com/blog/?p=614#comment-3352 Did you ever figure out a good solution to this? Did you ever figure out a good solution to this?

]]> By: Jeff http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1554 Jeff Fri, 07 Nov 2008 03:06:55 +0000 http://mightyohm.com/blog/?p=614#comment-1554 I picked up some ferrites and some cables with ferrites included. I'll give it a shot and see what happens. I picked up some ferrites and some cables with ferrites included. I’ll give it a shot and see what happens.

]]> By: Eric Wolf http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1518 Eric Wolf Thu, 06 Nov 2008 00:01:14 +0000 http://mightyohm.com/blog/?p=614#comment-1518 Is the interference getting into the cable, or the converter, specifically? Another quick and dirty fix might be to use some ferrite beads. I had to do that on some equipment that was installed in a Ford Ranger. Is the interference getting into the cable, or the converter, specifically? Another quick and dirty fix might be to use some ferrite beads. I had to do that on some equipment that was installed in a Ford Ranger.

]]> By: Jeff http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1515 Jeff Wed, 05 Nov 2008 23:34:58 +0000 http://mightyohm.com/blog/?p=614#comment-1515 Eric - It's in that standard cheapo rubbery plastic stuff that all USB peripherals come in these days - the kind that are embedded in the connector. I'd like to keep the computer and USB stuff off the chassis ground if possible. The last thing I want is for the starter motor to decide that my RS-232 cable is the lowest impedance to ground from the engine, however unlikely that seems. Eric – It’s in that standard cheapo rubbery plastic stuff that all USB peripherals come in these days – the kind that are embedded in the connector.

I’d like to keep the computer and USB stuff off the chassis ground if possible. The last thing I want is for the starter motor to decide that my RS-232 cable is the lowest impedance to ground from the engine, however unlikely that seems.

]]> By: Eric Wolf http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1514 Eric Wolf Wed, 05 Nov 2008 23:27:19 +0000 http://mightyohm.com/blog/?p=614#comment-1514 Is the converter in a metal enclosure? If so, ground it to the frame. If not, stick it in one, and then ground it to the frame :-) Is the converter in a metal enclosure? If so, ground it to the frame. If not, stick it in one, and then ground it to the frame :-)

]]> By: Tony http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1513 Tony Wed, 05 Nov 2008 23:15:32 +0000 http://mightyohm.com/blog/?p=614#comment-1513 Sounds like it needs optical isolation :) Sounds like it needs optical isolation :)

]]> By: Jeff http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1511 Jeff Wed, 05 Nov 2008 21:37:02 +0000 http://mightyohm.com/blog/?p=614#comment-1511 fiid - that's an idea I am working on. I'm actually thinking about building a ruggedized 50V isolated ESD protected usb-serial converter to solve the problem forever. :-) fiid – that’s an idea I am working on. I’m actually thinking about building a ruggedized 50V isolated ESD protected usb-serial converter to solve the problem forever. :-)

]]> By: Fiid http://mightyohm.com/blog/2008/11/noise-sensitivity-of-usb-serial-converters/comment-page-1/#comment-1510 Fiid Wed, 05 Nov 2008 21:35:01 +0000 http://mightyohm.com/blog/?p=614#comment-1510 I suspect that most of these converters don't fully implement the RS232 spec on the serial side. RS232 is really stringent about noise protection and voltage spike protection; and the components to operate at that spec are expensive; which is why most ports are RS232 compatable, not RS232 compliant. I wonder if some chokes and caps could be placed on the serial side of the converter to increase the resilience to noise? I suspect that most of these converters don’t fully implement the RS232 spec on the serial side. RS232 is really stringent about noise protection and voltage spike protection; and the components to operate at that spec are expensive; which is why most ports are RS232 compatable, not RS232 compliant. I wonder if some chokes and caps could be placed on the serial side of the converter to increase the resilience to noise?

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