6 How to Control the Frequency Converter
6.1 PPO Types
The PROFIdrive profile for frequency converters specifies a number of communication objects (Parameter Process data
Objects, PPO), which are suitable for data exchange between a process controller, such as a PLC, and frequency converters.
All PPOs are defined for cyclic data transfer, so that process data (PCD) can be transferred from the controller to the slave
and vice versa. Table 6.1 shows the PPO types available for the FC 102/FC 202/FC 301/FC 302/FCD 302.
PPO types 3, 4, 6, 7 and 8 are pure process data objects for applications requiring no cyclic parameter access. The PLC sends
out process control data, and the frequency converter then responds with a PPO of the same length, containing process
status data. The first two bytes of the process data area (PCD 0) comprise a fixed part present in all PPO types. The first two
words of the process data area (PCD 0 and PCD1) comprise a fixed part present in all PPO types. The following data (PCD 2
to PCD 9) are flexible for PCD write entries (9-15 PCD Write Configuration, and for PCD read entries (9-16 PCD Read Configu-
ration. The parameters can be parameterised with process signals from the list on parameter 9-23 Parameters for Signals.
PPO types 1, 2 and 5 are mixed process data objects for applications requiring and cyclic parameter access. These PPO types
has a PCD part where the PLC sends out process control data, and the frequency converter responds with a PPO of the
same length, containing process this is a feature like in PPO 3, 4, 6 and 8. In the front of the PCD data, the three PPO types
has the PCA (Parameter Characteristics Access) part. In the PCA data it is possible to read or write to the drives parameters,
with up to four byte of data.
Select the signals for transmission from the master to the frequency converter in 9-15 PCD Write Configuration (request from
master to the frequency converter). Select the signals for transmission from the frequency converter to the master in
9-16 PCD Read Configuration (response: FC → master). PPO types 1, 2 and 5 has a PCV part and a PCD part. The PCV
(Parameter Characteristics Value) allows the acyclic access to Parameters via the cyclical data exchange.
The choice of PPO type is made in the master configuration, and is then automatically recorded in the frequency converter.
No manual setting of PPO types in the frequency converter is required. The current PPO type can be read in
parameter 9-22 Telegram Selection.
Selection [1] Standard telegram 1 is equivalent to PPO type 3.
How to Control the Frequenc... Operating Instructions
24 Danfoss A/S © Rev. 2014-02-27 All rights reserved. MG90U302
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