Fluid Components International ST100 Series PROFIBUS PA - Manual (Page 7)

ST100 Series Profibus PA
Fluid Components International LLC 3
Operation
Functional Description
The ST100 is a Flowmeter with three flow classifications, volumetric flow, mass flow, and velocity flow. In addition, the ST100 family of instruments
offers process temperature and process pressure.
The ST100 can support up to 2 flow sensors, the output is presented as an average of the two flow sensors. The ST100 has the capability of viewing
the output of each sensor head.
In a two-sensor configuration, the cyclic data value for flow and temperature is the average of the two sensors.
Cyclic Operation Description
In the cyclic operation of the ST100 there are up to 4 possible output variables and they are formatted as a value and status structure. The first 4
bytes are the value in a floating-point format, and the fifth and last byte is the status byte. The class-1 master, typically a PLC, handles cyclic data.
The ST100 PROFIBUS PA is organized as a “Multi-variable Device”.
Flow 4 bytes (float) 4 bytes (float)
One of three flow types (Volumetric, Mass
Flow, or velocity).
Temperature 4 bytes (float) 4 bytes (float) One type only.
Totalizer 4 bytes (float) 4 bytes (float)
One of two (FCI internal, or Profile Total-
izer)
Pressure 4 bytes (float) 4 bytes (float) One type only.
The ST100 support both the “Classic Diagnosis” and the new “Condense Diagnosis”. The diagnosis selected depends on the
PROFIBUS PA master.
Cyclic Operation Setup
In PROFIBUS all process data is presented through the DPV0 layer, so that a class 1 master can interpret it.
A typical process data configuration for the ST100 instrument is made up of process Flow data, process Temperature data, and Totalizer data. The
Totalizer in this case is the ST100 native Totalizer. See configuration table below for this typical configuration.