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PROFIBUS connection (option) System 2020 XT C
ONNECT
8 - 6
ba75970e01 10/2012
8.5 Transmitted sensor data
8.5.1 Overview
Course of the data
transmission
The basis for data transmission between the PROFIBUS master and
IQ S
ENSOR
N
ET
is formed by the unique assignment of a sensor to its
sensor number (Sxx) in the IQ S
ENSOR
N
ET
system. The sensor num
-
bers are assigned by the system in the order in which the sensors are
recognized by the system.
The sensor number (Sxx) is the identification for a sensor. The sensor
number is always transmitted in the first byte of the output and input da
-
ta. Thus the PROFIBUS master can clearly query data of individual
sensors.
The data is transmitted in two steps:

The Profibus master transmits the request to the IQ S
ENSOR
N
ET
to
supply data for the sensor with a certain sensor number.

TheIQ S
ENSOR
N
ET
checks whether the requested sensor number is
present and returns the data for the sensor with the respective sen
-
sor number to the PROFIBUS master.
Fig. 8-3 Course of the data transmission in the PROFIBUS master
Read input data Read input data
Is sensor number identical
in input data and output data?
Is sensor number identical
in input data and output data?
Input data:
Process data for sensor
Input data:
Process data for sensor
Prompt data of a sensor
with a different sensor number?
Prompt data of a sensor
with a different sensor number?
Output data:
Allocate sensor number (Sxx) for a sensor
Output data:
Allocate sensor number (Sxx) for a sensor
no
no
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