ifm electronic RN3001 - Manual (Page 8)

Encoder with Profibus interface
8
When the terminal resistor is activated, the next bus (Bus Out) is decoupled�
The bus is only correctly connected if the encoder is installed on the terminal cap� If the encoder has
to be replaced during operation, the use of a separate active bus termination is recommended�
After the address has been set in the hardware and, if applicable, the terminating resistor has been
activated, the encoder can be put into operation�
8 Device configuration
Encoders with Profibus interface can be configured and parameterised according
to the requirements of the user�
In this respect the GSD file of the device is loaded into the projection tool� Various
encoder classes can be selected for the projection� Parameters and functionalities
of the device that can be set depend on the selected encoder class� ifm encoders
of the RM30xx and RN30xx series support all encoder classes described below�
Therefore the functionality is not restricted from the hardware side and is only
determined by the user� ifm encoders do not only provide the encoder classes
"Class 1" and "Class 2" described in the encoder profile but also encoder classes
with manufacturer-specific functions�
When configuring the device, configuration and parameter data are defined by
selecting the encoder class� This data saved in the Profibus master is transferred
once to the encoder when the system starts up (configuration and parameterising
phase – "DDLM_Set_Prm")� It is not possible to change configuration or
parameters during operation�
After the configuration and parameter data has been received, the encoder goes
into normal operation (cyclic data exchange – "DDLM_Data_Exchange mode")
in which, for example, the position value is transferred� The length and format of
the data exchanged are also defined when configuring the device by selecting the
appropriate encoder class�
9 Encoder classes
9.1 Class 1 and Class 2
The encoder classes Class 1 and Class 2 are the versions according to the
encoder profile defined by the encoder working group in the Profibus user
organisation (available from PNO indicating order no� 3�062)�