Specification; Overview - Pepperl+Fuchs FIELDBUS Manual

Compact Fieldbus Power Hub,Generic Interface

Specification

2 Specification
2.1

Overview

The FieldConnex
FOUNDATION Fieldbus H1 with redundant configuration as standard for eight segments. It
consists of a motherboard with sockets for plug-in modules: Two power supply modules per
segment and two diagnostic modules. The Power Hub is designed for use with fieldbus
systems in accordance with IEC 61158-2. This standard specifies how power and
communication are transmitted sharing one shielded twisted-pair cable. Communication
between field devices and a host system is established by modulating the data signal onto the
power stream utilizing Manchester Bus Powered (MBP) transmission.
All FieldConnex
features are redundancy, passive impedance generation, well-balanced circuitry, and low heat
dissipation. All active electronic components are located in the plug-in modules. Each module
holds the electronic components for only one segment, and two modules operate in redundant
configuration. When an exchange becomes necessary, only the smallest amount of electronic
components is exchanged compared to block configurations for power supplies. Modules can
be exchanged while the system is energized without the use of tools, thus ensuring very high
system availability.
Impedance generation prevents the data signal from being short circuited by the power
supply's low internal resistance. This impedance generation is designed with passive
components such as inductances and resistors with very long durability. A fully balanced circuit
and segment design is important for undisturbed fieldbus operation. An external disturbance
through EMI impacts both leads of the shielded twisted-pair cable symmetrically. The data
signal is thus undisturbed. Low heat dissipation allows highest packing density inside the
cabinet and a very long service life.
When applied to fieldbus in hazardous areas, the Power Hub feeds segments following the
High-Power Trunk concept for explosion protection. High power level on the trunk line is fed to
the field instrument via couplers such as FieldBarriers or Segment Protectors. The Power Hub
powers segment installed as non-arcing (Ex nA).
FieldBarriers enable live maintenance in Zone 0/1 as outputs are classified Ex ia. Thus, power
limitations of intrinsically safe explosion protection are overcome, enabling maximum cable
lengths and highest number of devices in any hazardous area.
Two plug-in Advanced Diagnostic Modules for fieldbus are available. These modules monitor
the physical layer online and in real time, enabling detection of degradation and faults during
operation. Measurement data and alarms are transmitted to the control room. They bring
visibility to the fieldbus physical layer, so it can be treated as an active component in Plant
Asset Management systems. Operators are enabled to decide on proactive measures to avoid
unwanted situations while the plant is running smoothly.
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Compact Power Hub is a high-performance power supply for
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Compact Power Hubs feature superior design elements. The main design
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