1 Features and System Configuration
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CJ-series PROFIBUS Slave Unit Operation Manual for NJ-series CPU Unit (W510)
The three masters form a logical token ring. When an active device receives the token message, it
can perform its master role for a certain period of time. During this time it can communicate with all
assigned slave devices in a master- slave communication relationship, and a DPM2 master can take
the initiative to communicate with DPM1 master devices in a master-master communication relation-
ship.
Multi-peer Communication
In addition to logical peer-to-peer data transmission, PROFIBUS-DP provides multi-peer communi-
cation (broadcast and multicast).
Broadcast Communication
An active station sends an unacknowledged message to all other stations (masters and slaves).
Multicast Communication
An active station sends an unacknowledged message to a predetermined group of stations (masters
and slaves).
DPM1
DPM2
DPM1
Token Passing
Polling
PROFIBUS
Passive stations
Slave devices
Active stations
Master devices
