Once upon a time it didn’t seem necessary to protect automation systems (PLCS’s) against hackers and people with bad intentions. They were connected to isolated networks and there was no link to the outer world. Nowdays engineers want to see how their machines are doing on the other side of the planet meaning that in some way there is a link between the automation system and the internet.

Whenever a computer that is connected to the plant bus and to the internet is infected with a trojan a hacker can gain access to the  plant bus from whereever he wants. Since the security on the plant bus is poor or unexistant the hacker will be able to connect to the PLC’s on the network.

During ‘Black Hat 2011′ Dillon Beresford reveald that he found ways to bypass the S7’s security measures and read and write data into the PLC memory, even when the system has password protection enabled. And on the S7-300 Beresford even found a command shell left in the firmware by Siemens engineers, that he can connect to and use to run commands on the system.

It’s a Unix-like shell where commands can be ran. Username: basisk; password: basisk. This shell is a “back door” to the system that can be used to gain access to automation controllers.

So, what can be hacked using this security issue? Every system that has a connection to the outer world! (network, usb stick,…)

Are we in danger? Let’s hope not. If the engineers of nuclear plants, water purification installation and other critical installations used their common sense while designing the plants. The controller of a critical plant should always be isolated from the outer world. Monitoring the plant can be done with separate sensors and controllers whenever necessary.

Since this article is about a typical Belgian product (and its problems) I will write it in dutch.

Het Digicorder probleem
Veel digitale kijkers die gebruik maken van de Digicorder van Telenet ondervinden na enkele jaren problemen. Deze gaan van af en toe een melding dat de stekker uitgetrokken moet worden om alle functionaliteiten te herstellen tot het continu herstarten van de Digicorder. De garantietermijn van de Digicorder bedraagt 2 jaar en die garantietermijn blijkt net iets korter te zijn dan de levenstermijn ervan. Wat weinig mensen weten is dat je voor nog geen 3 euro de Digicorder zelf kan herstellen.

De oorzaak van de problemen

Hoewel je zou kunnen denken dat de oorzaak aan de software ligt is dit veelal niet het geval. De eerste firmware versies van de Digicorder waren niet de beste maar tegenwoordig is de software behoorlijk stabiel. Waar het dan wel fout loopt bij de Digicorder is de hardware.

Na het openschroeven van de Digicorder wordt het probleem meteen duidelijk. Zeven condensatoren die bol staan of zelfs uitgelopen zijn.

Overzicht digicorder

Bolle en lekkende elco

De oplossing

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As HMI for the home automation over IP project I’m using a 7″ touchscreen. To get the best result from the screen I want to use it on it’s hardware resolution. This is 800×480 px, not a standard supported resolution. To get around the problem I installed Powerstrip, a very useful program to create custom timings and resolutions. After experimenting for a few minutes I had the touchpanel going at 800×480 px. Another job well done…

Finally some progress  in the home automation over IP project. The controller is put into it’s housing, there is some firmware written and there’s also some progress on the computer software.

To make it possible to mount the controller in a common electric cabinet it will be housed in a DIN Rail mountable enclosure.

DIN Rail housing

To bring the micro controller outputs to the exterior I made a PCB using the toner transfer method.

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It has been a while since I announced the home automation over ethernet project. It’s time to make some progress!

I’ve been writing some basic software for the microcontroller making it possible to switch leds on and off and change the IP and MAC address of the modules. Also on the hardware part some decisions have been made. As mentioned in the previous post the modules will be mounted on a DIN rail. The microcontroller will have it’s own housing. Outputs and inputs will have a separate housing making it possible to create different configurations.

For the creation of the circuit boards the “Toner Transfer” method will be used. This is a cheap and accurate method to create prototypes. When I start creating the PCB’s I will explain this method in detail.

The software running on the server will not be written in VB.net but in Java since I want to leave the option for Linux as operating system open. Below you find a screenshot of the main screen. This is really an early development version, but it gives an idea.

The next step, something for tomorrow, will be ordering some electric components to create the prototype modules. To be continued.=;;

There are several reasons to extend a VGA cable. A Media Center PC is a great tool to manage your music, movies, pictures etc. To avoid a noisy computer blowing in your ears while watching a movie a VGA extension cable could be a great help. Mounting your home theatre beamer on the ceiling is a good idea, but how to get there with the VGA signal? Extend it using cheap cat5 UTP cable!

Connect the cables as listed in the following table. Wire both connectors the same way.

The only drawback is the slightly notable ‘ghosting’ as a result of the difference in impedance with a regular VGA cable. With the extension I use (12m) the ghosting is only visible when showing black text on a whte background. But since the beamer is only used to watch movies, television and pictures I never had complaints about the quality. If you really want to improve the quality, an STP cable could be the solution.