Communication
Communication medium
10
Networking via PROFIBUS−DP
10.3
10.3.4
L
10.3−4
EDSPM−TXXX−9.0−11/2009
Data transfer between DPM 1 and slaves
The connection is established by DPM 1 via the MS1 channel. The connection to
the slave can only be established by the master that has parameterised and
configured the slave.
Service Description
Read The master reads a data block from the slave.
Write The master writes a data block to the slave.
Alarm The slave transmits an alarm message to the master. The master acknowledges
receipt. To prevent alarm messages from being overwritten, the slave can only transmit
a new alarm message if it has received the acknowledgement.
Alarm_Acknowledge The master transmits an acknowledgement to the slave, confirming that it has received
an alarm message.
Status The slave transmits a status message to the master. The master does not acknowledge
receipt.
Data transfer between DPM 2 and slaves
The connection is established by DPM 2 via the MS1 channel using the "Initiate"
service. One slave can maintain several active connections at the same time. The
number of connections is limited depending on the resources available in the
slave.
Service Description
Initiate / Abort Establishing or terminating a connection for the acyclic data transfer between DPM 2
and a slave.
Read The master reads a data block from the slave.
Write The master writes a data block to the slave.
Data_Transport The master writes user−specific data (defined in profiles) to the slave and, if required, it
reads data from the slave in the same cycle.
) Note!
For further information on the services and communication with
DP−V0 and DP−V1, refer to standard IEC 61158.
10.3.4 Communication medium
l The communication medium is an RS485 interface.
l The bus can be configured as line or tree topology.
l The bus structure under RS485 enables the reactionless connection and
disconnection of stations as well as the gradual commissioning of the
system. Subsequent enhancements do not affect the stations already in
operation. It is automatically detected whether a node has failed or just been
connected to the mains.
l PROFIBUS Gateway and PROFIBUS GatewayECO are provided with a 9−pin
Sub−D socket to ensure that they can be connected to the bus.
Services for the acyclic
parameter data transfer
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