Why the Holy Grail Is Different
© Doug Johnson, WRD, 7/31/02
Most "embedded modules" that are currently available
were designed with the intention that they be used in an end product
as is... in other words, they were designed to be products onto
themselves. The Holy Grail was conceived to facilitate the design
of custom controls. This difference shows up easily in the end
product.
If you use existing modules, such as PLC's, SBC's, PC/104, or any
other "use as is" hardware, the module will be easily
recognizable in the end product. If that same module is used in
another application, it will remain identical regardless of the
differences of the applications. The differences are resolved by
using other "modules" such as solid state relays, temperature
transmitters, analog to digital conversion modules, motor control/amplifier
modules, etc.
The Holy Grail is NOT intended to be used "as is" in the
end product. It is a reference design that includes the most common
industrial control requirements (on/off power output, proportional
power output, RTD/thermocouple/thermistor temperature input, motion
control, user interface, and many others). The purpose of the reference
design is to facilitate proof of concept work and provide a product
development platform. It can also be used "as is" for
pre-production performance testing. If all goes well, the next step
may be to re-package the control to fit within size and shape constraints.
The intention is to take the platform schematics, load them into
a PC layout workstation, and layout new printed circuit boards.
The value of the Holy Grail comes from the ability
to use a single hardware/firmware platform to cover product development
needs from proof of concept, through pre-production testing, and
then use the already tested schematics to re-package the control
for the production requirement. The fact that it facilitates the
design of a custom control in all phases of the development cycle
is what makes the Holy Grail different.
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