Commissioning
Prosonic S FMU95 PROFIBUS DP
56
Hauser
9.4.4
Configuration of the cyclic data telegram
• The general principles of cyclic data exchange between the measuring device and an
automation system (e.g. PLC) are described in Operating Instructions BA00034S,
"PROFIBUS DP/PA - Guidelines for planning and commissioning".
• As a prerequisite for cyclic data exchange, the correct GSD must have been loaded
into the automation system.
Data format
•
Analog values
In PROFIBUS DP, analog values are cyclically transmitted to the PLC in data blocks that
are 5 bytes long (modules). The measured value is represented in the first 4 bytes in the
form of floating point numbers in accordance with the IEEE standard. The 5th byte
contains standardized status information pertaining to the device. For details, see
BA00034S.
•
Digital values
In PROFIBUS DP, digital values are cyclically transmitted in blocks that are 2 bytes long
(modules). The first byte contains the digital value. The second byte contains the related
status information. For details, see BA00034S.
Modules for analog values
Each AI Block in Prosonic S makes a 5-byte module available for the cyclic data telegram
(from the device to the PLC). In line with the "Profile for Process Control Devices"
PROFIBUS specification, there are two options for each module:
•
AI (OUT)
The module is transmitted in the cyclic data telegram.
•
Free Place
The module is not part of the cyclic data telegram.
The option is selected via the configuration tool of the PLC. For details, see the Operating
Instructions of the manufacturer-specific configuration tool.
Modules for digital values (DI)
Each DI Block in Prosonic S makes a 2-byte module available for the cyclic data telegram
(from the device to the PLC). In line with the "Profile for Process Control Devices"
PROFIBUS specification, there are two options for each module:
•
AI (OUT)
The module is transmitted in the cyclic data telegram.
•
Free Place
The module is not part of the cyclic data telegram.
The option is selected via the configuration tool of the PLC. For details, see the Operating
Instructions of the manufacturer-specific configuration tool.
Modules for digital values (DO)
Each DO Block in Prosonic S makes a 2-byte module available for the cyclic data telegram
(from the PLC to the device). In line with the "Profile for Process Control Devices"
PROFIBUS specification, the following options are available for each module:
• DO (SP_D)
• DO (SP_D/CB_D)
• DO (RCAS_IN_D/RCAS_OUT_D)
• DO (RCAS_IN-D/RCAS_OUT_D/CB_D)
• Free Place
The option is selected via the configuration tool of the PLC. For details, see the Operating
Instructions of the manufacturer-specific configuration tool.
