TMT84 Commissioning
Endress+Hauser 33
!
Note!
The system units in the table correspond to the preset scalings transferred during cyclical data
exchange. However, in the case of customer-specific configuration, the units can differ from the
default value.
6.5.6 Output data
The display value provides the option to transfer a measured value calculated in the automation
system directly to the head transmitter. This measured value is purely a display value, displayed by
PROFIBUS
®
PA Display RID 261 for example. The display value contains 4 bytes with the measured
value and 1 byte with the status.
!
Note!
Only activate the data blocks that are processed in the automation system. This improves the data
throughput rate of a PROFIBUS
®
PA network.
A flashing, double-headed arrow symbol is shown on the optional display to indicate that the device
is communicating with the automation system.
6.5.7 System units
The measured values are transferred in system units, via cyclical data exchange, to the automation
system as described in chapter ’Group setup’ (UNIT N parameter).
6.5.8 Configuration example
Generally a PROFIBUS
®
DP/PA system is configured as follows:
1. The field devices to be configured (iTEMP
®
TMT84) are integrated in the configuration
program of the automation system via the PROFIBUS
®
DP network using the GSD file.
Required measured variables can be configured offline with the configuration software.
2. The application program of the automation system should now be programmed. The input and
output data are controlled in the application program and the location of the measured
variables is specified so that they can be processed further.
3. If necessary, an additional measured value conversion component must be used for an
automation system that does not support the IEEE-754 floating point number format.
4. Depending on the data processing type in the automation system (little-endian or big-endian
format) it may be necessary to change the byte order (byte swapping).
5. Once configuration has been completed, this is transferred to the automation system as a
binary file.
6. The system can now be started. The automation system establishes a connection to the
configured devices. The process-related device parameters can now be set using a class 2
master, e.g. with the help of FieldCare.
Input byte Process parameter Access type Comment/data format
0, 1, 2, 3 Display value Write 32-bit floating point number
(IEEE-754) representation
ä 31
4 Status display value Write -
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