Siemens SIMOVERT Master Drives 6SE70 Betriebsanleitung Seite 327

09.02
The following diagram shows the services and channels supported by a CBP2:
(Class 1 master)
MSCY_C1
Cyclic channel
PPO
PKW PZD
Job/ Setpoint/
response actual values
Parameter channel
Slaves (e.g. CBP, CB1) may only respond to received messages and are referred to as passive nodes .
PROFIBUS ( Pro cess Fi eld Bus) combines high baud rates (to RS485 standard) with simple, low-cost
installation. The PROFIBUS baud rate can be selected within a range of 9.6 kbaud to 12 Mbaud and is set for
all devices connected to the bus when the bus system is started up.
The bus is accessed according to the token-passing method, i.e. permission to transmit for a defined time
window is granted to the active stations (masters) in a "logical ring". The master can communicate with other
masters, or with slaves in a subordinate master-slave process, within this time window.
PROFIBUS- DP ( D istributed P eripherals) predominantly utilizes the master-slave method and data is exchanged
cyclically with the drives in most cases.
The user data structure for the cyclic channel MSCY_C1 (see picture above) is referred to as a Parameter
Process(data) Object ( PPO ) in the PROFIBUS profile for variable-speed drives. This channel is also frequently
referred to as the STANDARD channel.
The user data structure is divided into two different sections which can be transferred in each telegram:
PZD section
The process data (PZD) section contains control words, setpoints, status words and actual values.
PKW section
The parameter section (PKW - Parameter ID Value) is used to read and write parameter values.
When the bus system is started up, the type of PPO used by the PROFIBUS master to address the drive is
selected. The type of PPO selected depends on what functions the drive has to perform in the automation
network.
Process data are always transferred and processed as priority data in the drive.
Process data are "wired up" by means of connectors of the basic unit (drive) or via technology board
parameters, if these are configured.
Parameter data allow all parameters of the drive to be accessed, allowing parameter values, diagnostic
quantities, fault messages, etc. to be called by a higher-level system without impairing the performance of the
PZD transmission.
Siemens AG 6SE7087-6AK85-0AA0
Common Rectifier Operating Instructions
CPU
MSAC_C1
Acyclic channel
DS 0 DS 100
Diagnosis PKW
Job/
response
DriveMonitor
(Class 2 master)
MSAC_C2
Acyclic channel
PZD
PKW
Setpoint/
Job/
actual values
response
Process data channel
ENGLISH
Start-Up
4-53