LGB - a control - SingleChip-PC


The "Central Station"

of the system introduced here is a SingleChip-PC, which features a preinstalled DOS-like real-time operating system and all necessary resources like RAM, flash-disk, file system, ethernet, TCP/IP and a webserver as well as serial interfaces, too.

For the user, the SingleChip-PC remains a "block box" which he does not need to pay attention to at any time. Neither during operations nor when applying conversions or extensions to the layout.

How does it work ?

The SingleChip-PC's ethernet interface is used to communicate with the handheld or other computers incorporating TCP/IP protocols. The cards controlling the railway (switch, track and special modules) are connected to one of the SingleChip-PC's serial interfaces. This connection includes a conversion to RS485 signals. Both the SingleChip-PC and the controller cards are connected to the same 24V DC power supply.
The SingleChip-PC's IP-address needs to be adapted to your local network so that it can be used for controlling the railway. Furthermore a program is copied to the SingleChip-PC's file system which will handle communications between the handheld, other computers and the controller cards. This program will start automatically on power-up after adding it to AUTOEXEC.BAT (see picture on the right).

The transmission of control sequences from the handheld or another computer to the SingleChip-PC is done via simple HTML addressing.

"Phoning" your SingleChip-PC

The SingleChip-PC's webserver accepts the HTML instructions and checks them for logical correctness. If the check completes successfully, the instruction is converted to a controller-compatible format and is then passed to the controller which is meant to execute the command.

HTML controlling the layout's functions

A controller's feedback regarding a command's execution is converted to HTML by the SingleChip-PC and is sent back to the originating computer (f.i. the handheld) then. The feedback message is being displayed in a seperate frame (visibility configurable).

Superimposed feedback frame

More technical details and further information on the SingleChip-PC can be found on the manufacturer's pages.

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