Communication / PROFIBUS
09.2008
6SE7087-6QX70 (Version AK) Siemens AG
8.2-6
Compendium Motion Control
SIMOVERT MASTERDRIVES
Data is exchanged with the MASTERDRIVES in accordance with the
specifications of the PNO guideline "PROFIBUS profile for variable-
speed drives". PROFIdrive CBP and CBP2 V2.10 implement PROFIdrive
version 2 (PNO: Order No. 3071).
CBP2, V2.21 and later, implements PROFIdrive Version 3 (PNO: Order
No. 3172) as a compatible expansion. The useful data structure
described below is still supported.
For the drives, the guideline specifies the useful-data structure with
which a master can access the drive slaves by means of cyclical
MSCY_C1 data transfer. With MSCY_C1 data transfer, useful data is
divided up into two areas which can be transmitted in each telegram:
♦
The process data area (PZD), i.e. control words and setpoints or
status information and actual values
♦
The parameter area (PKW) for reading/writing parameters
−
e.g.
reading out faults
−
and for reading out information on the
characteristics of a parameter such as reading out the min./max. limits
etc.
The type of PPO (see next page) used by the PROFIBUS-DP master to
communicate with the converter can be configured from the master when
the bus system is started up. Which type of PPO is selected depends on
the task of the drive in the automation network. The process data are
always transmitted. In the drive, they are processed with the highest
priority and in the shortest time slots. The process data are used to
coordinate the drive with the other units in the automation network, e.g.
for power on/off, entering setpoints etc.
With the help of the parameter area, the user can access all the
parameters in the converter via the bus system as required. For example,
detailed diagnostic information, alarms and so on can be read out. In
this way, a higher-level system, (e.g. a PC), can be used to call
additional information for visualization of the drive without affecting
process data transmission.
The telegrams of cyclical data transfer therefore have the following basic
structure:
Protocol frame
Useful data
Protocol frame
(Header)
Parameters (PKW)
1)
Process data (PZD)
(Trailer)
PPO
1)
PKW: Parameter identifier value
NOTES
