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Have it your way — with Linux, of course

Oct 7, 2002 — by LinuxDevices Staff — from the LinuxDevices Archive — 133 views

[Updated Oct. 9, 2002] Sicom Systems Inc. announced that they are in the process of installing 160 Linux-based SL-18 point-of-sale (POS) systems in all of the Burger King restaurants in Puerto Rico.

Each Burger King installation consists of a network of web-enabled smart terminals running Linux, with each terminal having an embedded Apache webserver, integrated webbrowser, PDF viewer, and report package. All back office management functions — such as running real time reports or watching orders being taken real time in a 'virtual receipt' window — are possible from any computer having an industry standard browser which is connected to the restaurant network via a modem, or optionally through the Internet.

The systems are controlled by a customized Linux operating system implementation put together by Sicom. Each system contains a Sicom-developed custom computer board which is based on a National Semiconductor Geode system-on-chip processor (shown in the photo).

A larger photo of the Sicom SL-18 Linux-based POS system is available here.

Hardware overview

The internal single-board computer is based on a National Semiconductor 300MHz Media-GX Geode chipset, with 128MB of onboard RAM. An additional board takes care of power requirements, drives specialized POS devices, and provides automatic battery backup and uninterrupted operation in case of power failure.

The SL-18 is packaged with a 12-inch color, high-contrast tilting LCD touch screen panel in a metal case specifically designed for the quick-service restaurant industry. The terminals feature specialized POS devices, such as a magnetic card reader for credit card authorization and management authorization purposes, a 2 line by 20 character VFD customer display, and cash-drawer interfaces. Also included are external connectors for USB devices such as keyboard, mouse, and CD-ROM drive, serial ports for various peripherals, a pair of PCMCIA slots wired as IDE drives for fixed-disk and Flash memory card capability, and a built-in 10/100 Ethernet interface.

Sicom's Pen Tablet, also running an embedded Linux operating system, offers wireless connectivity for management functions as well as remote order taking. It provides up to 3.5 hours of full operation on battery power, or unlimited operation when docked in its charging cradle.

Software overview

Here is an outline of the key software components of the internal operating system environment . . .

  • Operating system:
    • Customized Linux, loosely based on Red Hat 6.1
    • Kernel version 2.4.16
    • Ext3 (journaling) filesystem
    • FTP and Telnet enabled to allow customers to access their data and to allow access for our support personnel
    • Apache 1.3.9 web server on the manager's terminal
  • Booting:
    • Manager system (server) terminal boots directly from 2 GB Type II PC Card HDD
    • Slave terminals use etherboot to load OS and required programs
  • GUI:
    • Customized version of TinyX (Xfbdev) utilizing a frame buffer
    • Customized Window Manager
    • Opera 6.02 web browser

On top of the above, proprietary software apps running in the terminals include . . .

  • Management CGIs — provide management edits and reports to any web-browser enabled terminal on the network. Literally hundreds of management functions are available, from simple employee clock-in/outs to inventory control to labor scheduling. Management reports are produced using PDF for portability.
  • POS touch screen application — implemented using GTK+ (1.2)
  • APM daemon for power management — detects powerfail conditions and allows continued operation of the terminal utilizing an internal battery.
  • Kitchen Screen daemon. Communicates with up to three dumb terminals used to display items to the kitchen staff as they are ordered. Orders and items can be reviewed and bumped as they are prepared.
  • SECNET/POS daemon — provides communication with onboard POS devices such as a magnetic card reader, customer VFD display, cash drawers, etc. Also provides specialized POS functions and remote file access (our solution to NFS).
  • 'STP' networking daemon — used for communications between applications and our daemons, STP utilizes UDP, adding error detection and recovery with timeouts optimized for a local network.
  • Print spooling daemon — similar in operation to lpd/lpr, but with increased reliability and options for automatically discarding print jobs based on number of jobs in a queue and time limit.

Why Linux?

After three years of intense research, Sicom's third generation system, the SL18TM, is now being offered. With two generations of product representing the most reliable system in the industry, it was imperative that the SL18TM have the same level of reliability with next generation functionality.

One year was spent selecting the OS for the project. NT, Windows, CE, Unix, QNX, and Linux were evaluated for reliability, functionality, supportability and cost. The clear winner in all the categories was Linux. Linux, with its multitasking and multi-user Kernel and industry solid utilities (Apache webserver, FTP server and X server for windows — just to name a few), was the clear winner.

Development process

With the GCC tool kit, Sicom converted all of its field proven C code to the Linux platform. After testing C modules in the original text-based programs, Sicom created a GUI based touch front-end for its order entry using GTK. The GUI front-end communicates with the original order-entry module via UDP.

Next was the project of making the text-based back-of-store modules look up to date (i.e. all report modules, electronic ordering, timekeeping, speed of service, bank deposits, labor scheduling, production control, etc.). One could just put a windows front-end on the existing code; however, Sicom chose to repackage all the code to work through a webserver and be viewed through industry standard browsers with the added functionality of a PDF writer and viewer. A long time problem has been printer compatibility, from one computer to the next. This is now solved.

It was determined during real-time testing that neither the use of TCP, NFS and LPD/LPR would meet the high standards of Sicom. TCP has been replaced by a custom Sicom UDP layer with quick fault detection and off line mode. NFS replaced by RFA which provides for a timely multi-terminal file access system. Replacing LPD/LPR by SLPD/SLPR provides efficient print job management (no print job hang-ups or back-ups due to hardware and no operator intervention).

About Sicom

Sicom is a provider of point-of-sale solutions for the fast-food industry. Caribbean Restaurants, a Franchisee of Burger King Corporation, owns and operates all of the Burger King Restaurants on the island of Puerto Rico and is one of the largest Burger King Franchisees.

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