Siemens SIMATIC MV420, Operating Instructions Manual

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Glossary
SIMATIC MV420 / SIMATIC MV440
408
Operating Instructions, 04/2013, A5E02371045-06
Counter
A counter registers the state changes (edges) of a digital signal. With each state change, the
counter increases (increments) or decreases (decrements) a value that is then evaluated by
SIMATIC S7 or a PLC.
CSV file
A CSV file is a text file for storage or for exchange of simply structured data; these files can
be read, for example, with Microsoft Excel.
CustomGUI
A custom user interface that communicates with the reader via the Web API.
Debouncing
Permanent electrical contact does not occur immediately when electrical switching or key
contacts are closed; the connection opens and closes several times within a fraction of a
second. With digital input devices (computer keyboards, input controllers on keypads, etc.),
this bouncing effect causes each occurrence of the contact to be registered as a separate
input (multiple input). Since the discovery of the phenomenon, various hardware and
software solutions have been developed. Counteracting this effect is known as debouncing
(debouncing circuit or routine).
DHCP client
Each device with network capability that supports communication with a DHCP server to
obtain dynamically leased IP configurations and other optional parameter information.
DHCP server
A computer on which the Microsoft DHCP service runs. This provides active DHCP clients
with dynamic configuration of IP addresses and related information.
Distortion
Image error that becomes evident in the image of a rectangular grid where the straight lines
are bent inwards or outwards.
DNS server
A hierarchically distributed database containing assignments of DNS domain names to
various data types, such as IP addresses. DNS allows computers and services to be found
based on user-friendly names and also allows other information stored in the database to be
found.