IMPORTANT!
Please read the following section before installing your product:
Octagon’s products are designed to be high in performance while
consuming very little power. In order to maintain this advantage, CMOS
circuitry is used.
CMOS chips have specific needs and some special requirements that the
user must be aware of. Read the following to help avoid damage to your
card from the use of CMOS chips.
Using CMOS circuitry in industrial control
Industrial computers originally used LSTTL circuits. Because many PC
components are used in laptop computers, IC manufacturers are
exclusively using CMOS technology. Both TTL and CMOS have failure
mechanisms, but they are different. Described below are some of the
failures which are common to all manufacturers of CMOS equipment.
The most common failures on Single Board Computers are over voltage of
the power supply, static discharge, and damage to the serial and parallel
ports. On expansion cards, the most common failures are static discharge,
over voltage of inputs, over current of outputs, and misuse of the CMOS
circuitry with regards to power supply sequencing. In the case of the video
cards, the most common failure is to miswire the card to the flat panel
display. Miswiring can damage both the card and an expensive display.
Multiple component failures:
The chance of a random component
failure is very rare since the average MTBF of an Octagon card is
greater than 11 years. In a 7 year study, Octagon has never found a
single case where multiple IC failures were not caused by misuse or
accident. It is very probable that multiple component failures indicate
that they were user-induced.
Testing “dead” cards:
For a card that is “completely nonfunctional”,
there is a simple test to determine accidental over voltage, reverse
voltage or other “forced” current situations. Unplug the card from the
bus and remove all cables. Using an ordinary digital ohmmeter on the
2,000 ohm scale, measure the resistance between power and ground.
Record this number. Reverse the ohmmeter leads and measure the
resistance again. If the ratio of the resistances is 2:1 or greater, fault
conditions most likely have occurred. A common cause is miswiring
the power supply.
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