Emerson Rosemount 5900C, Reference Manual

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Segment design
When designing a FISCO fieldbus segment a few requirements need to be considered.
Cabling has to comply with FISCO requirements as described in
Cable selection for the
Tankbus .
You will also have to ensure that the total operating current of the connected field devices
is within the output capability of the Rosemount 2410 Tank Hub. The 2410 is able to
deliver 250
(6)
mA. Consequently, the number of field devices has to be considered so that
the total current consumption is less than 250 mA, see Power budget .
Another requirement is to ensure that all field devices have at least 9 V input voltage at
their terminals. Therefore you will have to take into account the voltage drop in the
fieldbus cables.
Distances are normally quite short between the Rosemount 2410 Tank Hub and field
devices on the tank. In many cases you can use existing cables as long as the FISCO
requirements are fulfilled (see
Cable selection for the Tankbus ).
See chapter “The Tankbus” in the Rosemount 2410 Tank Hub Reference Manual for more
information on segment design of a Rosemount Tank Gauging system.
3.4.8 Typical installation
The example below ( Figure 3-27 ) illustrates a system with daisy-chained field devices on a
single tank. Terminators are installed at both ends of the fieldbus segment as required in a
F
OUNDATION
Fieldbus system. In this case terminators are enabled in the Rosemount 2410
Tank Hub and a field device at the end of the network segment.
In addition to the field instruments on the Tankbus, Figure 3-27 illustrates how an
instrument such as a pressure transmitter can be connected to the intrinsically safe 4 -20
mA analog input of the 2410 Tank Hub.
Maximum number of HART Slave Devices:
Passive current loop: 5
Active current loop: 3
(6) In Smart Wireless Systems the 2410 can deliver 200 mA on the Tankbus
Reference Manual Installation
00809-0100-5901 September 2019
Rosemount 5900C Radar Level Gauge 107