In a DeltaV SIS system, communication occurs over the following:
the Control Network
the LocalBus
local peer bus
remote peer bus
Control Network
The DeltaV Control Network provides communication between the
nodes in the DeltaV network. Refer to the
DeltaV S-series and CHARMs Hardware Reference manual
for complete information on the Control Network.
LocalBus
The LocalBus provides communication between DeltaV controllers
and Logic Solvers and between DeltaV controllers and SISNet Repeaters.
Local peer bus
Logic Solvers communicate with other Logic Solvers
and with local SISNet Repeaters
through the carriers over a 2 channel local peer bus. The same
message is broadcast over both channels. The local peer bus must be terminated
at both ends. The local peer bus is terminated at the left end through the
2-wide power/controller carrier and at the right end through a terminated one
wide carrier.
Remote peer ring
SISNet Repeaters hosted by one DeltaV controller communicate with
SISNet Repeaters hosted by a different DeltaV controller over a fiber-optic
remote peer ring. A local SISNet Repeater collects locally generated global
messages into a single message and sends it to the next SISNet Repeater in the
ring. Upon receipt of a message, the receiving SISNet Repeater broadcasts it to
its local peer bus and forwards the message to the next SISNet Repeater in the
ring. A global message is forwarded around the ring once. The primary SISNet
Repeaters form one fiber-optic ring and the secondary form a separate,
independent ring. SISNet Distance Extenders that convert multimode fiber-optic
signals to single mode fiber-optic signals can be used to extend the remote
peer ring