Operating Instructions
IS1 PROFIBUS 3.00 E
- Technical alterations reserved -
7
PROFIBUS DP interface for IS1+
1.3 Access procedure of the PROFIBUS DP
Class 1 masters are masters that are allocated one or more slaves. Only class 1 masters have write (setting
the outputs) and read (reading inputs) access to the slaves allocated to them. Class 2 masters only have read
access to slaves. Each slave can have only one class 1 master but several class 2 masters can be available
for each slave. A network can have several class 1 masters. However, only one class 1 master can have write
access to the slaves allocated to it. Masters can be both class 1 masters for one particular slave while they
are class 2 masters for other slaves.
Example:
Slaves A1 and A2 are allocated Master A as their class 1 master. Master A has no slaves allocated to it as
class 2 master.
Master B is allocated as the class 1 master of the Slave B1 and as the class 2 master of both Slave A1 and
Slave A2.
PROFIBUS DPV0 services (class 1 master)
Data_Exchange
Cyclic data exchange with a class 1 master, e.g. an automation system with one slave.
RD_Inp
Reading of the input data by a class 2 master, e.g. PC for configuration and diagnosis
or another automation system.
RD_Out
Reading of the output data of a slave by a class 2 master.
Slave_Diag
Diagnosis data are sent to the class 1 master.
Set_Prm
Configuration data are sent by the class 1 master to the slave (IS1).
Chk_Cfg
Transmission of configuration data by the class 1 master to the slave and checking of
the configuration data received by the slave.
Get_Cfg
Request of a class2 master to read the current configuration data of a slave.
Set_Slave_Add
Not supported! The slave address is set by operating keys on the 9440 CPM of the
IS1+ field station or via rotary switches on the Socket of the 9442 CPU.
PROFIBUS DPV1 services (class 2 master)
Initiate
open acyclic connection (C2 channel)
Read
read data acyclic
Write
write data acyclic
Abort
close connection
