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AS-i hits the jackpot for IGTSiemens open architecture pays off for new slot machine plant by
Paul Deas, President, Serra Systems, Inc., Healdsburg, CA
From Las Vegas and Atlantic City to riverboats and Indian reservations, America's love affair with the gaming industry has created lots of winners. At the top of the heap is International Game Technology (IGT), the largest slot machine manufacturer in the world. With nearly 70 percent U.S. market share and total revenues approaching $1 billion, it is a safe bet to say IGT has hit the jackpot. IGT's new generation of slot machines are a far cry from the "clink and clank" of first- generation one-armed bandits. New microprocessor-based hardware and sophisticated software allow IGT's customers to literally write their own specifications. The company must design graphics, payoff ratios and types of games for each casino, often changing from order to order. It's partly because of new technology that IGT sales have grown from about
5,000 units per year to nearly 100,000. This incredible growth spurred the
company to consolidate 17 of its small manufacturing facilities into a single
550,000 sq. ft. operation in Reno, NV. The new $86 million construction project
was on an extremely fast track. The plan called for the total integration of an
automated manufacturing system that would enable IGT to build customized slot
machines quickly and accurately.
AS-i works readily with any PNP-type field component. It is extremely fast,
providing up to 5 millisecond updates (compared to other two-wire schemes which
are up to five times slower).
Neat and CleanAS-i is gaining quick acceptance in the industry because it is neat and clean in setup or changeout. The field devices are attached to receptacles on AS-i slave modules which connect to flat, flexible, two-wire cables. The slaves have front and back plates that screw together, sandwiching the AS-i cable's rubberized sheath and making an electrical connection via pointed prongs.Each slave can be ordered in a variety of configurations and can be easily programmed with a hand-held unit. The master can control up to 248 binary elements. Needing only two slots in the PLC rack, the master has its own intelligence, scanning the slave addresses for I/O updates and making information available inside the four 16-bit address assigned to each of the two PLC slots. "This system really accelerated the installation process," said
Jeff King, industrial engineer for IGT. "Serra Systems preprogrammed all of
the slaves and marked the nodes so that installers knew exactly what field
devices to connect. It only took about two hours per each assembly line."
More Than Just Luck The
simplicity of Siemens' AS-i networking at the controller and field device levels
eliminated the headaches of a confusing wiring scheme, cut costs and
installation time. The IGT manufacturing lines have a very simplistic approach
to a fast-paced, but complicated assembly environment. The distributed control
concept maximizes flexibility for the manufacturer today - and provides an
easily reconfigurable line for the future. Siemens' AS-i, SIMATIC PLCs and
PROFIBUS communications system can easily solve any fast-track assembly line
project.
A High-Rolling Manufacturing Line IGT's new
manufacturing process is definitely a "high-roller." Slot machine
cabinets are assigned a bar code and positioned on pallets marked with RF tags.
Once loaded, scanners along the rolling assembly line identify the cabinet with
a customer's work order from the plant's main AS/400 computer. Parts necessary
to customize each machine are fed from a carousel to the proper manufacturing
cell. Operators install the various kit parts into the proper cabinet. Slot
machines are then sent to burn-in and testing; a staging area for shipment; or
to another area for rework. PLCs track I/O information along the lines with
overall process flow conducted by the AS/400.
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IGT selected FlorStor Engineering, Inc., as the systems integrator to design the
new manufacturing process. Subcontracted by FlorStor to develop the control
system, Serra Systems opted to design the programmable logic controller (PLC)
system around a distributed control concept rather than having one central PLC.
Seven SIMATIC PLCs and 12 PC-based workstations provide the bottom two levels of
the control system hierarchy. The third level is IGT's AS/400 computer. The
design reduced wiring costs, time for installation and troubleshooting, and
provides greater flexibility in manufacturing. All of the PLCs communicate via
PROFIBUS. Because of its twisted pair concept, PROFIBUS also reduced wiring
costs and installation time. To accelerate construction of the control system,
FlorStor also selected Siemens' AS-i "two-wire" bus technology.