Emerson Rosemount 2410 Reference Manual page 35

Reference Manual
00809-0100-2410
Tank Gauging system, a trunk is typically located between the Rosemount 2410 Tank Hub
and a splitter or the last device in a daisy-chain configuration. Generally, one terminator is
placed in the fieldbus power supply, and the other one in the last device in the fieldbus
network.
Note
Ensure that there are two terminators on the fieldbus.
In a Rosemount Tank Gauging system the Rosemount 2410 Tank Hub acts as power
supply. Since the tank hub normally is the first device in the fieldbus segment, the built-in
termination is enabled at factory.
Other devices such as the standard version of the Rosemount 5900S Radar Level Gauge,
the Rosemount 2230 Graphical Field Display, and the Rosemount 2240S Multi-input
Temperature Transmitter also have built-in terminators which can easily be enabled by
inserting a jumper in the terminal block when necessary.
When adding new devices at the end of an existing F
termination is moved to the farthest field device in order to fulfill the requirement on
locating the terminator at the end of the trunk. However, in case a field device is added to
the network with a short cable, this rule may be slightly bent by leaving the terminator in
its original position.
Fieldbus segment design
When designing a FISCO fieldbus segment you will have to make sure that cabling
complies with FISCO requirements as described in
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 tank hub is able to
deliver 250
that the total current consumption is less than 250 mA, see
Since the field devices on the Tankbus must have at least a 9 V input voltage at their
terminals, you will have to take into account the voltage drop in the fieldbus cables. In
many cases distances are relatively short between the Rosemount 2410 and field devices
on the tank and you may use existing cables as long as the FISCO requirements are fulfilled
(see Cable selection for the
Typical characteristics for such a cable is:
Table 3-3: Typical Characteristics of Instrumentation Cable
Parameter
Loop resistance
Inductance
Capacitance
Cross-sectional area
The Rosemount 2410 outputs 12.5 Vdc. Considering the minimum voltage supply of 9 V
on the field device terminals, a maximum voltage drop of 3.5 V on the Tankbus can be
allowed. At a maximum current consumption of 250 mA (12.5 Vdc) with all field devices
(9) In Smart Wireless Systems the Rosemount 2410 can deliver 200 mA on the Tankbus
Rosemount 2410 Tank Hub
(9)
mA. Consequently, the total number of field devices has to be considered so
Tankbus).
Fieldbus network, the
OUNDATION
Cable selection for the
Power budget.
Value
42 Ω/km
0.65 mH/km
115 nF/km
2
0.75 mm (18 AWG)
Installation
December 2019
Tankbus.
35