News on the Lammert Bies website
- Nov. 11 2010
- Browser Header Checker
- With each request to a webserver, a browser send a number of header lines which give the webserver information about the client configuration. These header lines are normally not seen by webusers, but can now be made visible with the new on-line Browser Header Checker page on this website.
- Feb. 16 2010
- IPTables firewall page
- A firewall is a software or hardware implementation of a filter which tries to block undesired traffic over a computer network, while allowing all other traffic. Linux has a built in firewall system based on the iptables filter rules in the kernel. This page explains how this firewall can be configured to protect a Linux based computer or network.
- Jan 17. 2010
- HDMI interface page
- One of the new popular digital interfaces is the HDMI interface. It is able to transport both audio and video signals at a high rate between a large number of devices. A page has been written with the most common properties of this interface. The HDMI interface is not only used on computers, but also on settop boxes, VCRs, game consoles etc. It has rapidly replaced the VGA and DVI interface in computer applications.
- Jan 11. 2010
- Time synchronisation with Garmin GPS
- GPS receivers are mostly used for position calculation, but they can also be an excellent source for accurate time. I have connected a Garmin GPS to one of my servers and its clock now runs with an absolute error of just a few microseconds. The page which describes the process and how you can do it yourself is now available on this site.
- Jan 4. 2010
- USB cable length page
- For many users of USB, it is not always clear what the maximum cable length is they can use for a specific purpose. A new page about the USB cable length explains why the maximum lengths are how they are, which physical property limits them and how longer distances can be bridged with USB.
- Jan 3. 2010
- Bluetooth interface page
- Most communication interfaces described on this website use cables for the data transfer. Nowadays many communication is however performed through the ether. One of the best known wireless interfaces is Bluetooth which was developed to connect small battery operated devices to all kind of equipment. I have no dedicated a page to the Bluetooth interface.
- Jan 2. 2010
- CRC connectors page
- The USB standard started with only two types of connectors, but with the introduction of smaller devices and more functionality the number of available USB connectors has significantly increased. A new page now summarizes all USB connectors with their use and properties.
- Dec 1. 2009
- CRC calculation page with Ajax
- One of the most visited and loaded pages is the CRC calculation page. In the original setup, every touch of the Calculate button caused a full reload of the page. The page has now been rewritten in such a way that only the changing table with CRC values is reloaded from the server. This decreases the response time for the user and lowers server load.
- Dec 26. 2008
- DIY electronics pages
- Besides computer interfacing and software development, I have done a lot of electronics development in the past. Many of these projects are small and suitable for a larger
audience. I have therefore decided to make the most interesting projects available on-line.
- Apr 8. 2008
- VoIP introduction page
- Computer technology evolves and what once was leading edge technology is now a legacy from other times. To prevent this site from becomming a legacy of the past I am currently
working on a series of pages describing new protocols and technologies in communications. Today the first page about Voice over IP has been released.
- Aug 22. 2006
- Start of German version of website
- Today is one of the special days of this website. The first page in the German language went life. It is the page about RS232 cables. Writing in the local language of visitors opens a whole new world. The rest of the site will be converted to German in the comming time. There is however no fixed schedule.
- Jul 12. 2006
- Tutorial on RS232 to USB converters
- Many visitors are confused by the word serial which is both used for the RS232 port, and the USB port on the computer. I often receive emails asking how to connect these two ports. This can however not be done directly, a special converter and driver software is needed to make RS232 working over an USB line. I have written a new page about the specific problems arising from these converters.
- Jun 14. 2006
- Unitronics RJ11 cabling system added
- The PLC manufacturer Unitronics uses an interesting serial connection system with RJ11 connectors. The system is symmetrical to allow for direct interconnection between PLCs with both RS232 and RS485. Pinouts for this interface have been added to this website. Also common layout for interconnection and programming cables are shown.
- Mar 16. 2006
- RS232 software shop opened
- Many of the visitors of this website are not only seeking cable solutions for their problems, but also software. I have now added an RS232 software shop, with links to several communication software and libraries. All software can be bought and downloaded directly.
- Nov 24. 2005
- Free counter removed
- Since 1998, I have used the free Netstat Basic counter script on the site to keep track of the most important pages on this site. I have never had any problems with this counter. Unfortunately, at September 1st this year, the free service has been sold to a German ad company which relaunched the service under the name Webstats4u. Within a few days this company added a popup ad script to the counter code, resulting in unwanted SPAM popping up when some of the pages on this site were loaded. Because I am not visiting my site very often, it took some time for me to realize that the ads were generated by the counter code on my pages. After I discovered this I immediately removed all offensive code from my sites.
- I would like to apologize for the inconvenience that users may have felt the last months because of these unaccepted advertising tactics.
- Aug 5. 2005
- Modbus interface description
- There are a handful of interfacing standards in industrial communications. The Modbus interface—already developed in 1979—is the most widely used interface. PLC manufacturer Modicon created this standard and then allowed every other manufacturer to implement the interface in their equipment. Today I put a
tutorial about Modbus
on the website.
- May 21. 2005
- Description of Yost standard
- The Yost standard—defined by Dave Yost in 1987—is one of the best ways to connect RS232 over RJ45. I have added a
with the description and pictures of the needed conversion adapters to the website.
- May 7. 2005
- Added RS-485 information page
- The already 40 years existing communication standard RS-232 is more and more replaced
by the more versatile USB standard. But for scientific and industrial communication, RS-232's
nephew RS-485 plays a more important role than ever. Therefore I have added an
RS-485 information page
to the website. Plans are to cover also RS-422 and RS-423 in the near future.
- January 11. 2005
- Added on-line CRC calculation form
- Until recently most of the site has been written in plain HTML code to be as compatible
as possible with all sorts of browsers. Because of the current possibility to do scripting
at the hosts side with PHP, more intelligent functionality can be added without compromising
this choice. Therefore now an
on-line CRC calculation page
has been added which calculates
the CRC16, CRC32, and CRC-CCITT values for a given string without the need for java scripting
enabled at the user's side.
- January 3. 2005
- Speed increase main menu
- The loading time of the main menu has been increased by combining all small menu buttons
into two large image files. Especially for users connected over a slow line, or far away from
the image server this speed increase will be noticable.
- January 3. 2005
- Moved large files to second server
- Let me first wish you the best for 2005.
- Because of the ever increasing traffic to the website, a second webserver is now operational
for the large files like pictures and datasheets. This split in servers will probably provide
enough bandwidth capacity for the comming years. If you encounter any problems as the result of
this move, please contact me.
- December 27. 2004
- RS232 serial printer cable page rewritten
- The information about serial printer cables has been completely rewritten. An explanation
why printer cables differ from normal null modem cables has been added. New is also
the information of some specials. The information has been moved from the
general RS232 cable page to a
new dedicated page on the site.
- December 26. 2004
- RS232 spy/monitor cable information added
- Until now, only brief information was available on the site about sniffing RS232 communication
between two devices. The information has now moved to a
where solutions for both
half duplex and full duplex communication are discussed. Also new in the wiring diagrams is the
loopback of the handshake signals at the spy computers side. This prevents some software
from blocking the input data.
- December 24. 2004
- DEC MMJ information added
- Until now, only very limited space on the site was used for the DECconnect cabling system with
MMJ plugs. As this information becomes more difficult to find on the web I have written a
designated to all the cables and adapters used by DEC in the past.
- December 20. 2004
- New website
- Lammert Bies' new website is released to the web. The information of the previous site has been
transferred and where neccessary updated. New is the menu which makes it possible to chose every page
directly. Many visitors had problems to find the needed information right away and therefore the site map
was the most visited page of the site :-(
Also new is the quick links menu at the left which points to interesting and relevant other pages.
The more studying you did for the exam,
the less sure you are as to which answer they want.
SECOND LAW OF APPLIED TERROR