Comments for Steve's Software Trek

Comment on Wireshark and BACnet MS/TP by Peter

Peter — Mon, 16 Jan 2012 07:36:14 +0000

I’ve modified the program to allow the selection of 76800 as a baud rate as it will work directly with some serial port drivers.
I use the USOPTL4 and it will work for the most part with that – I do get some receive errors on the port which are not being seen by my devices or the router which mey be down to a problem with my hardware setup or the USOPTL4 baud rate not being close enough to 76800 for comfort.

Comment on Daylight savings time by Marceline F.

Marceline F. — Fri, 09 Dec 2011 20:46:08 +0000

Thank you for this informative post!! And no, I do not enjoy, nor am I used to, waking up earlier

Comment on BACnet Leader of the Pack Awards by Ed

Ed — Wed, 30 Nov 2011 06:48:55 +0000

Hi Steve
Well Done!! And you sooooo deserve it!
Ed

Comment on Wireshark and BACnet MS/TP by skarg

skarg — Sat, 26 Nov 2011 16:35:13 +0000

Thanks for the bug report/fix on the baud rate problem. I have corrected it in the svn repository, and will release new binaries soon.

Comment on Wireshark and BACnet MS/TP by Michel D

Michel D — Fri, 25 Nov 2011 19:54:14 +0000

I forgot to say that this problem is in the V0.6.0

Comment on Wireshark and BACnet MS/TP by Michel D

Michel D — Fri, 25 Nov 2011 19:35:39 +0000

In the main.c file of the mstpcap project, there is an ordering function call problem in the main routine.

The function RS485_Initialize() is called before the RS485_Set_Baud_Rate(). This is why even you want to set the port to an other baud rate than 38400, it always takes the 38400 baud rate.

Just put the RS485_Set_Baud_Rate() before the RS485_Initialize() function and it will do the good job.

Comment on Wireshark and BACnet MS/TP by skarg

skarg — Fri, 14 Oct 2011 22:27:06 +0000

The latest mstpcap utility and friends is available at the BACnet Protocol Stack site hosted by SourceForge.net. Since we still update various things in the tools and in the stack, the download link is a moving target. It is currently at 0.6.0, and can be found here:
http://prdownloads.sourceforge.net/bacnet/bacnet-tools-0.6.0.zip?download

One of the handy things that mstpcap does is display some capture statistics, and so we added the ability to scan an existing capture file and produce those statistics again. The option is “–scan” followed by a space and a capture file name.

I also improved the timing resolution to 1ms on Windows.

Comment on Wireshark and BACnet MS/TP by Trevor

Trevor — Fri, 14 Oct 2011 16:48:35 +0000

I have been trying to get this to work for a little while now and it seems like its my capture program that isn’t working right. When I type in 300 it auto bauds to the 38400 and doesn’t even try to fake the 76800 at 300. I was wondering where I can get the capture program that allows 300 capture.

Comment on Wireshark on Ubuntu not as root by Parménides GV

Parménides GV — Wed, 03 Aug 2011 19:27:12 +0000

Hi everybody!

If you are in Debian or in Ubuntu (I suppose the same happens with all Debian derivatives as Mint), you can do this directly executing the next command (as root):

dpkg-reconfigure wireshark-common

I read this by a reference on the wiki of Wireshark (http://ur1.ca/4ugx2).

Comment on Interrupt Safe Ring Buffer Library by Lei

Lei — Fri, 01 Jul 2011 23:30:41 +0000

The absolute index method only wraps around then the buffer size is a divisor of the counter’s capacity. So if the buffer size is a power of two and a unsigned integer counter is used, the counter would always wrap around.

Comment on BACnet Bill by Kathleen Swan

Kathleen Swan — Thu, 16 Jun 2011 17:32:33 +0000

Thank you for this tribute to my beloved husband, Bill.
It has been heartwarming to see how his life made a difference.
The photos capture him well. Could copies be sent to me, please?

Comment on BACnet Bill by Ernie Bryant

Ernie Bryant — Wed, 08 Jun 2011 13:14:50 +0000

I am so sorry to get this news. Bill was so special and such a good friend to me and everyone else. His gentle spirit kept the sometimes heated BACnet meetings in focus and he was a strong leader. He was such a help to me when I needed advice on how to write the Navy BACnet Spec. I will miss him very much!

Ernie Bryant
Retired Navy Civilian Little Creek

Comment on Create favicon.ico with Ubuntu Linux by Ubuntu – How to Create and Host favicon.ico Files on Apache « PricklyTech

Mon, 11 Apr 2011 03:52:21 +0000

[...] http://steve.kargs.net/hosting/create-a-website-faviconico-with-ubuntu-linux/ [...]

Comment on Create favicon.ico with Ubuntu Linux by Julia

Julia — Sun, 23 Jan 2011 03:17:07 +0000

What he said. Last time I did this, I used png2ico, but it’s pretty old code and I couldn’t get it to compile. Your solution was refreshingly simple, and unlike ppmtowinicon allows a transparent background. Thanks!

Comment on Interrupt Safe Ring Buffer Library by skarg

skarg — Sat, 08 Jan 2011 13:44:03 +0000

Hi Joaquim,

head minus tail will only return zero when they are equal, which is the only time that the buffer is empty, even if the value of head reaches the maximum value of an unsigned integer.

The concept is exploiting unsigned integer overflow in C:
http://en.wikipedia.org/wiki/Integer_overflow
“In the C programming language, signed integer overflow causes undefined behavior, while unsigned integer overflow causes the number to be reduced modulo a power of two, meaning that unsigned integers “wrap around” on overflow. ”

There is more discussion of the various types of Circular Buffers at Wikipedia from the link in the article:
http://en.wikipedia.org/wiki/Circular_buffer

Best Regards,

Steve