Baumer GE-GB-GXxxx - Manual (Page 39)

Manual_ProfibusDPV2_BIDE_EN.docx 39/41 Baumer IVO GmbH & Co. KG
22.11.12 Villingen-Schwenningen, Germany
Example:
Vvalue = dec. 500.000.000
Converted in hexadecimal format = hex. 1DCD6500
Split in block “lo” (4 digits from the right) = hex. 6500
Split in block “hi” (4 digits at left) = hex. 1DCD
Converted into decimal format block “lo” = dec. 25.856
Converted into decimal format block “hi” = dec. 7.629
8.2. FAQ: Operation
8.2.1. Position readout
In line with PROFIBUS DP-V2-encoder-profile, the encoder applies telegram 81 of the ROFIdrive profile (see
6.3.) for cyclic communication in clock-synchronous operation with cyclic and clock-synchronous transmission
of 12 bytes input data and 4 bytes output data.
Conversely to DP-V0, access to input and output data is only enabled by implementing a clock-synchronous
alarm in the project. Only the alarm can access the E/A section of the clock-synchronous slave. Siemens
controls utilize functions SFC126 and 127 in clock-synchronous OBs (OB6x) to update the partial process
images.
Afterwards input and output data are accessed as usual.
Direct access by peripheral input and output words is not possible.
8.2.2. How to set and save a preset value?
In line with PROFIBUS DP-V2-encoder-profile, the encoder applies telegram 81 of the ROFIdrive profile (see
6.3.) for cyclic communication in clock-synchronous operation with cyclic and clock-synchronous transmission
of 12 bytes input data and 4 bytes output data.
Defining a preset position value and performing a preset operation are two separate procedures. The actual
stored value enables acyclic readout and alteration using parameter 65000 of the encoder profile. Default
setting is 0. The preset parameter is saved non-volatile using parameter 971 (see 6.9.8.).
The preset operation is enabled by setting bit PR
of output word G1_STW1 to „1“.
If the operation was successful, the Preset Acknowledge bit of input dataword G1_ZSW1 is also set to „1“.Bit
PR now should be reset.
For maximum alignment of mechanical position and preset value the preset should only be set with idle
encoder shaft. Inferior requirements however also enable the setting operation with running shaft.
With „Class3“ parameterization the preset function is disabled.
A preset operation has always to be performed after having programmed the required resolution or direction
of rotation (cw/ccw).
8.2.3. What is the LED in the bus cover for?
The bus cover provides at rear an integrated multi-colour LED indicating the encoder operating status. In
particular upon commissioning and in case of error it is providing first information on the system status. For
the respective status description refer to 6.2.