5 Operation PROline Prosonic Flow 93 PROFIBUS-DP/-PA
66 Endress+Hauser
5.3.4 Acyclic data exchange
The acyclic data transmission is used to transmit parameters during the commissioning,
during maintenance or to display other measured variables that are not contained in the
cyclic data traffic.
Generally, a distinction is made between Class 1 and Class 2 master connections.
Depending on the implementation of the field device, it is possible to simultaneously
establish several Class 2 connections.
Theoretically, a maximum of 49 Class 2 connections can be established to the same
field device.
Two Class 2 masters are permitted with Prosonic Flow 93. This means that two Class
2 masters can access Prosonic Flow 93 at the same time. However, you must make
certain that they do not both attempt to write the same data, since otherwise the data
consistency cannot be guaranteed.
When a Class 2 master reads parameters, it will send an interrogation telegram to the
field device specifying the field device address, the slot/index and the expected data
record length. The field device will answer with the requested data record, if the
record exists and is the correct length (byte).
When a Class 2 master writes parameters, it will send the address of the field device,
the slot/index, record length (byte) and the record. The field device will acknowledge
this write job after completion.
A Class 2 master can access the blocks that are shown in the illustration below.
The parameters which can be operated by the Endress+Hauser operating program
(Commuwin II) are shown on Page 68 ff. in the form of a matrix.
Fig. 61: Function block model for Prosonic Flow 93 PROFIBUS-DP/-PA
Esc
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PB
Physical
Block
TB
Transducer
Block 1...2
TOT
Totalizer
Function
Block 1...3
AI
Function
Block 1...8
PROFIBUS-PA
Automation control
system
F06-93PBxxxx-02-xx-xx-en-000
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