SSD Drives DIGIVEX Motion PVD 3554, Руководство пользователя и по вводу в эксплуатацию

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DIGIVEX Motion - PROFIBUS
7
PVD 3554 GB 01/2004
2.1 Cyclical data transmission
DIGIVEX Motion is controlled through the cyclical PROFIBUS-DP channel. Moreover, this same
channel can be used for exchanging parameters.
The structure of useful data for the cyclical channel is defined in the PROFIDrive Profile version
2.0, and is called PPO (Parameter Process Data Object). This structure is used by the master to
access drive slaves by exchanging cyclical data.
2.1.1 Useful data structure in accordance with PROFIDrive Profiles V2.0
and V3.0
Useful data structure according to the PPO
The useful data structure in cyclical transmission is divided into two sections which can be
transmitted in each telegram:
Useful data
Protocol frame
(header)
PKW parameters PZD process data
Protocol frame
(trailer)
PPO
• PZD, process data area, that is to say, control words or status information.
• PKW, parameter area for reading / writing drive parameters.
It is possible, when configuring the master, to define the type of PPO (see below) with which the
master is to access the drives when the network is starts up. The type of PPO selected depends
on the task assigned to the drive in the automation system.
Process data is automatically transmitted. They are processed as top priority in the shortest time
slots in the drives. The drive is controlled by process data; e.g. On / Off, etc.
The parameter area gives the user complete access to all parameters and variables in the drive
via the bus. It is possible, for example, to write a target position or to read detailed information
concerning diagnosis, fault messages, etc.
DIGIVEX Motion supports two types of PPO from amongst those defined in the PROFIDrive
Profile version 2.0:
• PPO1: PKW, parameter area with 4 words and 2 words of PZD, process data.
• PPO3: PKW, without parameter area with - 2 words of PZD, process data.