GE Industrial Solutions AF-600 FP Profibus DP - Manual (Page 8)

1.6 Technical Overview
1.6.1 Network Topology
Single master
- PLC communicates with messages of constant length
- Fits time-critical requirements
- Cyclical transmission via PPO types
- Extended diagnostics
Illustration 1.1: PROFIBUS DP V0
1.6.2 Network Topology
Multiple master
Features of a Master class 1 connection
- Cyclical data exchange (DP V0)
- Acyclical read/write on parameters
- Extended diagnostics
The acyclical connection is fixed, and cannot be changed during operation.
Features of a Master class 2 connection:
- Initiate / Abort acyclical connection
- Acyclical read/write on parameters
The acyclical connection can be established (Initiate) or removed (Abort) dy-
namically even when a master class 1 is active on the network. The DP V1
acyclical connection can be used for general parameter access as an alter-
native to the PCV parameter channel.
Illustration 1.2: PROFIBUS DP V1
The PROFIBUS DP extension DP V1 permits acyclical as well as cyclical data communication. This feature can be used by a DP master class 1 (e.g. PLC), as well as
a DP master class 2 (e.g. PC tool).
AF-650 GP/AF-600 FP Profibus DP Operating Instructions
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