FCU 500, FCU 505 · Edition 02.17
59
Fieldbus communication via Ethernet
9 Fieldbus communication via Ethernet
Profinet and Modbus TCP are manufacturer-independ-
ent, open standards for industrial Ethernet. They cover
the requirements for automation technology (manufac-
turing automation, process automation, drive applica-
tions with or without functional safety).
Profinet and Modbus TCP are bus variants for fieldbus
communication, optimized for speed and low connec-
tion costs.
1
2
3
BCU 5xx
BCM
BCU 5xx
BCM
BCU 5xx
BCM
L1
BUS
FCU
P
HT
BCM..B2 = PROFINET
BCM..B4 = Modbus TCP
SPS
The basic function of Profinet and Modbus TCP is the
exchange of process and required data between a
controller (e.g. PLC) and several distributed devices
(e.g. BCU/FCU).
The signals from the devices are read into the controller
cyclically. There, they are processed and are then out-
put to the devices again.