Appendix MSX-E3701-DIO
9
Appendix
9.1
Glossary
ADC
= A/D converter
Buffer
The buffer is used for the temporary storage of
information that is only needed at a later time.
Cascading
Cascading means connecting multiple similar
elements together to enhance their individual
effect. The individual elements must be such
that the outputs of a given element are
compatible with the inputs of the subsequent
element in terms of values and functionality.
Counter
A counter is a circuit that counts pulses or
measures pulse duration.
Digital signal
A digital signal is a digital representation of a
constantly changing value or other piece of
information. Digital signals consist of a finite
number of values. The smallest possible
difference between two digital values is
referred to as the resolution. Digital signals are
discontinuous in terms of value and time
ranges.
Driver
A driver is a series of software instructions
written specifically to manage particular
devices.
Edge
Edges can either be rising or falling.
Logic levels are defined for processing and
displaying information. In binary circuits,
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. The rising
edge is the transition from the status “0” to
“1”; the falling edge is the opposite transition.
EMC
= Electromagnetic Compatibility
The definition of the VDE regulation 0870
states: Electromagnetic compatibility is the
ability of an electrical installation to function
satisfactorily within its electromagnetic
environment without unduly affecting its
environment and the equipment it contains.
Ethernet
The Ethernet is a baseband bus system
originally developed in order to connect mini-
computers. It is based on the CSMA/CD access
method. Coaxial cables or twisted-pair cables
are used as the transmission medium.
The transmission speeds are 10 Mbit/s
(Ethernet), 100 Mbit/s (Fast Ethernet) and
1 Gbit/s or 10 Gbit/s (Gigabit-Ethernet). This
widely used technology for computer
networking in a LAN has been standardised
since 1985 (IEEE 802.3 and ISO 8802-3).
Ethernet technology is now common practice in
the office environment. After making even very
tough real-time requirements possible and
adapting the device technology (bus cables,
patch fields, junction boxes) to the harsh
application conditions of the industrial
environment, Ethernet is now also increasingly
used in the field areas of automation
technology.
Ground line
Ground lines should not be seen as potential-
free return lines. Different ground points may
have small potential differences. This is always
true with large currents and may cause
inaccuracy in high-resolution circuits.
www.addi-data.com 55
