Cyclic Data Transfer; Acyclic Data Transfer - Endress+Hauser TMD 834 Betriebsanleitung

Chapter 3 Profibus
Block model of TMD 834
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3.4 Cyclic Data Transfer

The cyclic data telegram of TMD 834 has the following structure:


TMD 834 PLC (input data)
Index output data
0, 1, 2, 3 temperature
4 status
Status codes
TMD 834 uses part of the status codes defined by the PROFIBUS user organization
(PNO):
Status code
hex. (dez.)
0Fh (15)
40h (64)
80h (128)

3.5 Acyclic Data Transfer

The block model of TMD 834
With acyclic access, the control system is able to control the parameters of the blocks
listed below.
The TMD 834 software contains three different blocks which correspond to the
PROFIBUS-PA profile definitions:
• Physical block
In the Physical block there is device specific information such as tag number,
software version etc.
• Transducer block for temperature
The Transducer block contains the meter data.
• AI block (AI = analog input)
This universal function block provides the control system with all parameters for the
processing of the temperature measuring variable.
TMD 834
Data item Data format/remarks Factory setting (unit)
32-Bit floating point
number (IEEE-754)
see status codes
Meaning
device failure
non-specific
O.K.
TD
Transducer
Block
PB
Physical
Block
TMD 834
°C
-
Device status
BAD
UNCERTAIN
GOOD
AI
Function
Block
PROFIBUS-PA