SMAR LD303, Operation And Maintenance Instruction Manual, Page: 19 / 110

Installation
1.11
When the sensor is in the horizontal position, the weight of the fluid pushes the diaphragm down,
making it necessary a Lower Pressure Trim see Figure 1.8.
DIAPHRAGM SENSOR
SENSOR IN THE VERTICAL POSITION
SENSOR IN THE HORIZONTAL POSITION
HEAD OF THE FLUID
DIAPHRAGM SENSOR
Figure 1.8 - Sensor Positions
NOTE
Please refer to the General Installation, Operation Manual and Maintenance Procedures Manual
for more details.
NOTE
Please refer to the General Installation, Operation and Maintenance Procedures Manual for
more details.
Bus Topology and Network Configuration
Wiring
Other types of cable may be used, other than for conformance testing. Cables with improved
specifications may enable longer trunk length or superior interface immunity. Conversely, cables
with inferior specifications may be used subject to length limitations for trunk and spurs plus possible
nonconformance to the RFI/EMI susceptibility requirements. For intrinsically safe applications, the
inductance/ resistance ratio (L/R) should be less than the limit specified by the local regulatory
agency for the particular implementation.
Bus topology (See Figure 1.9) and tree topology (See Figure 1.10) are supported. Both types have a
trunk cable with two terminations. The devices are connected to the trunk via spurs. The spurs may
be integrated in the device giving zero spur length. A spur may connect more than one device,
depending on the length. Active couplers may be used to extend spur length.
Active repeaters may be used to extend the trunk length.
The total cable length, including spurs, between any two devices in the Profibus should not exceed
1900 m.
The connection of couplers should be kept less than 15 per 250 m. In following figures the DP/PA
link depends on the application needs.