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a) Ishida's QX-1100 tray sealer
d) Baldor MicroFlex e100 Ethernet-compatible servo driveA new generation of networked motion controltechnology using 100 Mbits/sec Ethernet-compatible servo motor drivesare making a breakthrough in the speed and flexibility of food tray sealing. The availability of this technology has helped Ishida, a manufacturer of food weighing and sealing equipment, re-think its control system architecture and achieve step-change improvements in speed.
Instead of the combination of servo and pneumatic actuation axes used on previous machines, Ishida's latest QX-1100 tray sealer employs servo motors throughout, controlled using Baldor's Ethernet-compatibleMicroFlex e100 drives. The speed and predictability of movement provided by the servo drives allows Ishida to accelerate the throughput forthis form of food processing automation, allowing sealing speeds of upto 200 trays/minute, which is up to twice as fast as many existing solutions.
The 100 Mbits/second speed of the network also simplifies the control system. It allows the machine's complex motion to be managed by a single controller with simple cabling. This eliminates several multi-axis motion controllers and dozens of wires that would conventionally be required.
In total, 12 servo motor axes are usedin the QX-1100. Six control the machine's dual infeed lanes. Two drive lugged chains that provide precise movement of the food trays through the filling process. Four more drives control take-off and spacing conveyor functions, to collect and precisely position the appropriate number of trays before entry into the sealing area.
Ishida chose to implement the machine using a standard Ethernet network. The drives are controlled by sending movement commands to axes as required, with predictability ensured by simple mechanisms including isolating themachine network to provide a known environment, and adding some collision avoidance software.
As a move is required, the embedded machine controller, Ishida's own-design hardware, issues the relevant motion commands using Baldor's Mint language. The availability of simple to use keywords in Mint, for all the movements required, were important for Ishida when developing this new machine, reducing the softwareeffort.
"The high level nature of the Mint language was a phenomenal help in minimising the timescales for this new-generation machine," says Ian Hodgson, Chief Software Engineer at Ishida Europe. "Thelanguage reduced what could have been a difficult software project toa predictable task taking around a month in total, and also giving usa very modular software which can be upgraded with ease. Baldor evenadded a new command into the Mint library for us, to improve the efficiency of communication with axes over a standard Ethernet network."
Another key facet of the Ethernet-connected control system architecture is simpler wiring. The 12 drives are dispersed in two controlpanels, and connect to the controller via a simple network cabling arrangement and some hubs. This simplifies the electrical system buildingeffort required, allowing the sophisticated new machine to compete well with lower performance alternatives.
"With conventional motion controller hardware we could easily have required four separate controllers to achieve the same result," adds Hodgson. "Not to mention the huge amount of wiring that would have been necessary for the 12 axesand encoders. We simply could not have produced the machine in the same compact footprint, and at same cost, without this new generation ofEthernet motion control technology."
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