2
016-
06
6
Fieldbus Power Hub,Motherboard for Gateway and Power Supply Modules
Product Specifications
2
Product Specifications
2.1
Overview and Application
The motherboard is a system component of the FieldConnex
®
Power Hub, a modular fieldbus
power supply for 4 segments. It is the wiring interface for one gateway, one advanced
diagnostic module, and 4 power supply modules. The power supply supports explosion
protection, e. g., the high
–
power trunk for long cable lengths and high device counts. The
Power Hub supports advanced diagnostics for fast fieldbus commissioning and online
monitoring.
The Power Hub may be installed in Zone 2 or Class I, Division 2 hazardous areas.
Types of protection are Ex ec (increased safety) for Zone 2, gas groups IIC, IIB, IIA, and non-
incendive for use in Class I, Division 2, gas groups A, B, C, and D.
Dedicated power supply modules limit the output voltage safely according to IEC 60079–11. In
combination with Fuchs Segment Protectors, the outputs are specified Ex ic. Thus,
live maintenance at the field device level is permitted.
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 a shielded
twisted pair cable. Communication between field devices and a host system is established by
modulating the data signal onto the power stream. For this, Manchester Bus Powered (MBP)
data transfer technology is used.
The main FieldConnex
®
Power Hub design features are passive impedance generation, well-
balanced circuitry, and low power dissipation. All active electronic components are located in
the plug-in modules. Each module holds the electronic components for 1 segment. When an
exchange becomes necessary, only few electronic components need to be exchanged when
compared to block configurations for power supplies.
Impedance generation prevents the data signal from being short-circuited by the low internal
resistance of the power supply. This impedance generation is designed with passive
components such as inductances and resistors with long durability.
A fully balanced circuit and segment design is important for undisturbed fieldbus operation. An
external disturbance through electromagnetic interference (EMI) impacts both leads of the
shielded twisted pair cable symmetrically. The data signal is thus undisturbed. Low power
dissipation allows highest packing density inside the cabinet and a long useful lifetime.
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 device via couplers such as FieldBarriers or Segment Protectors. The Power Hub
powers segments installed as increased safety (Ex ec) for Zone 2.
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.
A plug-in advanced diagnostic module for fieldbus is available. This module monitors 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. This brings
visibility to the fieldbus physical layer, so it can be treated as an active component in plant asset
management systems. On this basis, operating personnel can decide on proactive measures
to avoid unwanted situations while the plant is running smoothly.
The following table summarizes the main features and benefits of the Power Hub:
