Addi-Data APCI-3003 Technical Description page 38

Appendix
Calibration of the INL error alone is not
possible.
Input impedance
The input impedance is the ratio between
voltage and current at the input terminals
when the output terminals are open.
Input level
The input level is the logarithmic ratio between
two electrical values of the same type (voltage,
current or power) at the signal input of any
receiving unit. This unit is often configured as a
logical level related to the input of the circuit.
The input voltage corresponding to logic "0" is
between 0 V and 15 V and the voltage
corresponding to logic "1" is between 17 V and
30 V.
Interrupt
= IRQ
An external event indicating that the CPU
should suspend its current task to service a
designated activity.
Level
Logic levels are defined for processing and
displaying information.
In binary switches, voltages are used for digital
values. Here, the two voltage ranges "H" (high)
und "L" (low) represent the information.
The "H" range is closer to plus infinity; the "H"
level corresponds to digital 1. "L" denotes the
range closer to minus infinity; the "L" level
corresponds to digital 0.
Limit value
Exceeding the limit values, even for a short
time, can easily result in the destruction of the
component or the (temporary) loss of
functionality.
LSB
= Least Significant Bit
LSB is the lowest order bit in a digital quantity.
www.addi-data.com
Operating voltage
The operating voltage is the voltage to the
device in sustained operation. It must not
exceed the maximum sustained voltage, and all
unfavourable operating conditions, such as
possible mains power surges for over a minute
when the device is switched on, must be taken
into account.
Optical isolation
Optical isolation means that two networks are
only connected through an optoelectric
transmitter and receiver with no electrical
continuity between the two networks.
PTC
= Positive Temperature Coefficient
The best-value resistance sensors are either
specified as PTC or NTC thermistors. A PTC
thermistor has a positive temperature
coefficient, hence, "PTC".
Resolution
The resolution indicates how precisely a signal
or value is held within the computer.
Short-circuit
A short-circuit is an electrical circuit in a device
of lower resistance than that of a normal
circuit, typically resulting from the unintended
contact of components, and consequent
accidental diversion of the current.
Short-circuit current
A short-circuit current is the current between
two short-circuited terminals.
Timer
A timer is used for adjusting time-dependent
program processes between the processor and
peripheral devices. It contains counters that are
mostly independent of each other and can be
programmed like a programmable I/O module
via a control word register for different
operating types.
38
APCI-3003