6
6
1.4
Intrinsic Safety
The H1 physical layer supports Intrinsic Safety (IS) applica-
tions with bus-powered devices. To accomplish this, an
Intrinsically Safe barrier or galvanic isolator 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 net-
work. The FISCO model considers the capacitance and
inductance of the wiring to be distributed along its entire
length. Therefore, 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 maxi-
mum of 110 mA for Class II C installations and 240 mA
for Class II B installations.
FISCO certifying agencies have limited the maximum seg-
ment length to 1000 meters because the FISCO model does
not rely on standardized ignition curves.
The PULSAR Model R86 FF is available with entity IS,
FISCO IS, FNICO and non-incendive approvals (explosion
proof–future).
58-641 PULSAR Model R86 Pulse Burst Radar Transmitter - F
OUNDATION
fieldbus
™
Instruction Manual
