Glossary - Siemens SENTRON PAC RS485 Manual

Glossary

American Wire Gauge
American Wire Gauge is a number assigned to a specific conductor or wire cross-section.
Each AWG number represents a jump of 26% in the cross-sectional area. The thicker the
wire, the smaller the AWG number. A copper wire with AWG 10 has a diameter of 2.54 mm,
a cross-sectional area of 5 mm² and a resistance of 1 Ohm over a length of 304.8 m. With a
reduction of 3 AWG, e.g. AWG 10 to AWG 7, the cross-sectional area and the mass (weight)
are doubled. The DC resistance is halved. With a reduction by 6 AWG the diameter is
doubled. For conductor cross-sections to 107.2 mm² = AWG 4 / 0, also AWG 0000.
Baud rate
The baud rate is the rate of data transmission. It indicates the number of bits transferred in
one second.
Broadcast
Multicasting. With the broadcast procedure, the master sends a request to address "0". This
directs the information to all slave devices on the network. Slave devices do not respond to
broadcast frames.
Bus
Shared transmission path over which all bus nodes are connected. It has two defined ends.
Bus system
All stations physically connected to a bus line form a bus system.
Data bit
The number of data bits describes how many bits a character is mapped to for transmission
purposes.
Diagnostics
The detection, localization, visualization and further evaluation of errors, disturbances and
messages.
Provides monitoring functions which are executed automatically when the system is in RUN
mode. This reduces startup times and standstill times. Plant availability increases.
PAC RS485
Manual, 02/2008, A5E02091800B-01
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