REXROTH IndraDrive Fc FCS01, Operating Instructions Manual

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Rexroth IndraDrive FCS01.1 Control Communication - Field Busses and Protocols
15-57
DOK-INDRV*--FCS01*****-IB01_EN-P
I/O messages
I/O messages are used to transmit process data. An I/O message
generally has a producer (sender). It can have several consumers
(receivers), however. The process data can either comprise 8 bytes (non-
fragmented) or be distributed among several telegrams (fragmented).
Polling A polled connection corresponds to a master-slave-connection: A master
transmits data cyclically to the slave. The slave responds by transmitting
its status data.
Bit strobe In a bit strobe connection, the master transmits an 8 byte telegram to all
connected devices. Each node is assigned exactly one bit. As all nodes
receive the telegram simultaneously, a synchronous reaction can be
executed. The individual nodes' reaction to this bit is application-specific
and must be known to the master. The bit strobe telegrams are
unconfirmed.
Fig. 15-79: DeviceNet Protocol
DeviceNet Bus Description
Bus structure
Elements Description / data
Bus elements Topology linear (serial bus system)
Nodes max. 64 nodes,
depending on the driver modules used;
standard drivers can drive approx. 100 nodes;
Segments max. 32 nodes per segment
Repeater Used for 33 nodes or more
Interface Via serial interface RS 485
Bus terminator With resistors at both ends
Transmission
physics Cable specification Line type A acc. to EN 50 170
Cable design 5-strand line according to DeviceNet specification
Recommended cable type Surge impedance: 135 ... 165
Ω
Capacitance per unit length < 30 pF / m
Loop resistance 110
Ω
/ km
Strand diameter 0.64 mm
Strand cross-section > 0.34sqmm
Shielding minimum requirement single-shield;placed on both sides;
Wiring arrangement,
distances, shielding Inside and outside of control cabinets at least 20 cm distance
to other lines with voltages > 60V;
Fig. 15-80: Bus structure DeviceNet