Encode
Modes
Dec 2021
ATM60 / ATM90 / KHK53 21
5 Encoder Modes
The Profibus DP specification, level DP-V0, only defines the cyclical data traffic between a mas-
ter and a slave. Each download/upload of the parameter data must be complete before the cy-
clical data exchange is started. The checking of diagnostic data, in case of error[s], is also em-
bedded in the cyclical data traffic.
The encoders only support the basic DP functions according to DP-V0 specification.
There are three main states:
• Stop: No data transmission between DPM1 and encoder.
• Clear: DPM1 reads the input information from the encoder and holds the outputs in
failsafe condition.
• Operate: cyclical data traffic operation, via polling
5.1 Cyclical Data Transmission
Data transmission between the DPM1 and the encoder is divided into three phases:
• Parameterisation
• Configuration
• Transmission of the I/O data (data exchange)
5.1.1 Parameterisation
The encoder receives a set of parameterisation data according to the encoder profile (see 8.3.2)
5.1.2 Configuration
The encoder receives one (1 byte), which contains the configuration setup, according to the en-
coder profile (see 8.4).
This setup, also called Module Config, determines how the data is ultimately put together once
I/O data transmission has started.
5.1.3 I/O Data Transmission
Further information see „Data Types” 6.4 and “Data Exchange Mode” 8.5.
5.2 Specification of the Encoder Data
Essentially, the encoder is an input/output device. This means that the master’s encoder data
is used by the bus and itself produces data for the bus. The functionality of the output data is
reduced to the ‘Preset value' data type.
The table shows the properties of all data types supported across the different module configu-
rations, also called Data Assemblies.
Data type Data size Assembly (Ax) Prod_Update
(x1)
Position value 4 bytes 1, 2, 3, 4, 5, 6 0.250 ms
Speed value 2 bytes 3, 4, 5, 6 50.000 ms
Time stamp 2 bytes 5, 6 0.250 ms
Cons_Update
Preset value 4 bytes 2, 4, 6 ~ 20 ms -
(x2)
(*1)
Time for generating a new data value (input to bus).
(*2)
Time for the correct processing of the output data (writing to EEPROM).
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