Controls News 13
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Main theme: Lean automation |
Technology
Example of a dedicated
controller in refrigeration
technology.
Dedicated controllers often have to be replaced 2 or 3 times
over the life cycle of an installation
Lean automation devices:
there is always a USB port.
Source of the problem:
The control loops are closed over
the control/management levels.
Open network connections alone generate many er-
ror messages that have to be processed. How many
network failures are due to faulty input or mistakes?
How much stress does this cause, and how much
time does it waste? Lean automation should elimi-
nate this problem source while still using Ethernet.
The solution is simple – each automation devicemust
have a standard USB port in addition to the Ethernet.
As a universal interface, USB is always operational,
everyone has it and it carries no serious risk of error.
The only manufacturers who would dispense with a
USB port are those who build minimum-cost equip-
ment to make large amounts of money on service.
The opposite scenario: «non-lean» technology
In contrast to the lean technology described above,
we include here a number of examples of «non-lean»
technology. In these cases, the comprehensive aims
of lean automation cannot be achieved and circum-
stances actually work against them.
Non-lean
Control loops closed over control levels –
«
non-lean» because of the lack of transparen-
cy and a guaranteed cycle of forced innovation
How can you lower costs for automation devices and
force customers to be loyal? An example would be
the use of PC technology’s superfluous computing
power at the control/management level for simple
control tasks at the field level. Software updates and
operating system upgrades mean cyclic insecurity,
stress and expense. Due to the short life of PC tech-
nology, PC hardware has to be changed between
three and five times during the life cycle of an auto-
mation system in a building. These are the most an-
noying highlights of automation that is anything but
lean.
Non-lean
Dedicated controllers represent and enormous
risk and are extremely costly when they fail
Moreover, the «Perfect Fit» status is not achievable,
because the automation system cannot be adapted
simply or securely.
If the entire functionality of a piece of automation
hardware is contained on a circuit board, develop-
ment and production will cost less than connecting
individual system modules via a high-quality con-
nector system. Moreover, the majority of dedicated
controllers are not freely programmable. Their lim-
ited functionality cuts costs on presales, support and
distribution. That is the main reason why dedicated
devices are lower in price.
There are many disadvantages to dedicated control-
lers. Often, the fixed I/Os already prove to be insuf-
ficient at the first adjustment or expansion. This re-
sults in limited communication options. So dedicated
controllers can be sold two to three times over the
life cycle of the facility – a lucrative business for the
manufacturer.
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