Rockwell Automation 2711 PanelView 550/900 Profibus Communications User Guide User Manual
Page 20
PROFIBUS DP Communications
20
Publication 2711-6.3
Note: Performing a multiplex module data exchange requires a
number of poll cycles from the DP Master to the PanelView
terminal. During each of those poll cycles real time data is
constantly being exchanged.
The diagram below shows the relative position of the Real Time and
Multiplex modules in the data packet sent between the DP Master
and the PanelView terminal. The modules reside in the DP Master’s
database in the same relative position.
Real Time Output Data
Hsk
BlockOut
BlockIn
Multiplex Block Output Data
DP Master to PanelView
Real Time Input Data
Hsk
BlockOut
BlockIn
Multiplex Block Input Data
PanelView to DP Master
Up to 16 Words
1 Word
15 Words
Up to 16 Words
1 Word
15 Words
Real Time Module:
Multiplex Module:
Hsk:
Handshake Bit
BlockOut:
Block ID sent by DP Master (7 bits)
BlockIn:
Block ID requested by DP Master (7 bits)
Block Data
Real Time Module:
Multiplex Module:
Hsk:
Handshake Bit
BlockOut::
Block ID received by PanelView (7 bits)
BlockIn:
Block ID sent by PanelView (7 bits)
Block Data