Siemens SITRANS FUS060 Operating Instructions Manual page 25

PROFIBUS PA interface
The PROFIBUS PA variant of the SITRANS FUS060 differs from the 4 to 20 mA / HART version in
the bus interface and the omission of the digital output 2. This means that the basic functions
of the device including the operation and display remain basically the same. Function blocks 1
to 6 take care of the interface tasks to the bus.
①
The microprocessor interprets the bus command, initiates device-internal actions and provides measured values,
status and device data on the bus.
②
The device internal electronics are isolated from PROFIBUS PA by the potential isolator.
③
The bus interface contains the transmit and receive circuits for the bus system.
④
The electronic current limiter ensures that no illegally high current flows in the event of an error. This avoids bus
overloading and ensures that data communication with the other unaffected users is maintained.
⑤
The reverse polarity protection enables the bus cables to be connected at any terminals and makes installation errors
almost impossible.
⑥
An EMC filter prevents malfunctions in the case of electromagnetic interference.
Figure 3-6 Block diagram of the bus link
Scope of function
SITRANS FUS060 with PROFIBUS PA provides the following measured values and values derived
from measured values using PROFIBUS and local display.
• Flow (volume or mass flow)
• Sound velocity
• Ultrasonic amplitude
• Quantity (volume or mass) net, forward and reverse
An upper and lower limit can be specified for all measured values. An appropriate message is
indicated in the measured value status when a limit value is reached. Diagnostic messages are
also indicated in the event of malfunction or special states.
The device has a wide range of setting facilities, for example, measuring range scaling,
definition of the flow direction, residual flow suppression, attenuation of measured values etc.
The settings are made on the PROFIBUS or using the local keyboard with menu guidance.
The quantity values (volume and mass) are derived from the flow value by accumulation
(volume or mass forward from all positive flow values, volume or mass reverse from all negative
flow values, and volume or mass net from all flow values with the correct sign) and also have
setting facilities for the limit values but no scaling.
The flow values can also be issued as a frequency or pulse sequence at "digital output 1".
Status information on quality and compliance with limit values is provided with the measured
values. Further diagnosis data can be called up if there are device errors.
SITRANS FUS060 with PROFIBUS PA
Operating Instructions, 09/2021, A5E02225054-AD
Description
3.5 PROFIBUS communication
25