Orion Instruments Jupiter 2xx - Manual (Page 23)

46-648 Jupiter Magnetostrictive Transmitters 23
An important requirement of Fieldbus devices is the inter-
operability concept mentioned above. Device Description
(DD) technology is used to achieve this interoperability.
The DD provides extended descriptions for each object and
provides pertinent information needed by the host system.
DDs are similar to the drivers that your personal computer
(PC) uses to operate peripheral devices connected to it. Any
Fieldbus host system can operate with a device if it has the
proper DDs for that device.
The most recent DD and Common File Format (CFF) files
can be found on Magnetrol’s web site at magnetrol.com or
fieldbus.org.
1.8.4 Intrinsically Safe
H1 supports Intrinsic Safety (IS) applications with bus
powered devices. To accomplish this, an IS barrier is placed
between the power supply in the safe area and the device in
the hazardous area.
H1 also supports the Fieldbus Intrinsically Safe Concept
(FISCO) model which allows more field devices in a network.
The FISCO model considers the capacitance and inductance
of the wiring to be distributed along its entire length. The
stored energy during a fault will be less and more devices
are permitted on a pair of wires. Instead of the conservative
entity model, which only allows about 90 mA of current, the
FISCO model allows a maximum of 112 mA for Class II C
installations and 319 mA for Class II B installations.
FISCO certifying agencies have limited the maximum
trunk length to 1000 meters and spur length to 30 meters
because the FISCO model does not rely on standardized
ignition curves.
The Orion Jupiter is available with an entity IS, FISCO IS,
and explosion proof approvals.