Weidmuller SAI Active Universal Pro Series, Руководство пользователя

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Appendix
Resolution
Bit accuracy is a measure of the exactness of digital
measurement and calculation operations. An accu-
racy of 8 bits, for example, 1 byte corresponds to an
accuracy of 1/(2^8) = 1/256 or 0.390625% steps.
This is particularly important when converting from
an analogue signal to a digital value if the meas-
urement value of a sensor (temperature, pressure
or similar) is to undergo digital further processing.
Rotary coding switch
Rotary coding switches are used to make settings.
They use a minimum of space. These settings are
usually coded in decimal or hexadecimal formats.
RS-485
As a so-called differential voltage interface the RS-
485 interface operates with +5V (high) and 0V (low)
by which the non-inverted signal is transmitted via
one strand and the inverted (or negative) signal via
the other. As distortions have the same effect on
both signals, the difference between both signals
remains (virtually) the same and can be used for
evaluation purposes.
An RS-485 connection constitutes a serial data
transmission, which means the bits are transmitted
one after the other on a line.
RTR
Remote Transmission Request. A request for data
(data request telegram) with the same ID as used
for data transmission.
SAI
The acronym SAI stands for Sensor Actuator Inter-
face. It is a compact-designed distributor or collec-
tor of signal lines.
SAI distributor
Please see SAI.
Sampling period
The sampling period determines in which time inter-
val an analogue input is converted. The sampling
period for the SAI-AU AI/AO/DI can be set between
5 ms and 250 ms.
SDO
Service Data Object - communication objects for
configuration and for access to entries in the object
directory.
Segment
The PROFIBUS network consists of one or more
segments. The maximum extension of a segment
depends on the baud rate being used. Up to 32
PROFIBUS stations can be connected in each
segment.
Settings range
Range on the SAI in which the configuration of the
hardware is carried out; for example, the module
address.
Shielding
The shielding is necessary to protect cables from
radiated noise.
Supply voltage
Voltage with which the device is supplied. The
power supply in automation engineering is usually
18 to 24 VDC.
SYNC
SYNChronization object
Temperature coefficient
The temperature coefficient is a relative change to a
physical variable resulting from a change in tem-
perature of 1 K (Kelvin).
Torx screwdriver
Torx is an improvement to the cross-head screw
and hexagon-socket (Allen) as a tool receiving
socket, for example in counter sunk screws.
The profile is similar to a six-pointed star with
rounded off points and corners – more or less a
wave form. Part of the Textron Group, Camcar was
the inventor and patent holder. In the meantime, the
Torx patent has run out and the hexalobular internal
drive feature has been incorporated in international
standards.
T-piece
This is offered to provide uninterrupted feed of the
supply voltage and the Fieldbus.
T-pieces are connected straight onto the consumer
and interconnected with the supply voltage or Field-
bus by means of male and female connectors.
Transmission rate
Please see Baud rate.
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