wtw MIQ/2-PR, Operating Manual, Page: 16 / 28

Interface for the PROFIBUS MIQ/2-PR
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3.5 GSD file
The GSD file contains all necessary information on the Profibus module
and is required by the configuration program of the Profibus master.
The current GSD file is provided on the Internet under www.WTW.com.
3.6 Transmitted sensor data
3.6.1 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 transferred 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.

The IQ S
ENSOR
N
ET
checks whether the requested sensor number
is present and returns the data for the sensor with the respective
sensor number to the PROFIBUS master.