REXROTH Fv Series, Instruction Manual

Page: 192 / 222

7. The converter can not communicate in the process of auto-tuning; the
communication will be recovered when auto-tuning is complete.
12.2.7 Communication Networking
Networking
The communication network is shown in fig. 12-21 "ModBus networking" on
page 190 , with a PC, a PLC or an external computer and various frequency
converters, which are connected by shielded twisted pair cables via
RS232/485 adapters. The maximum length of 232 network cable connection
is 15 meters. Network terminal slaves need external resistance with a recom‐
mended value of 120 Ω, 0.25 W.
Fig.12-21: ModBus networking
Cables may only be connected when drive is
turned off!
WARNING
Recommendations on Networking
● Use shielded twisted pair cable to connect RS485 links.
● ModBus cable should be adequately away from power cables (30 cm in
minimum).
● Avoid crossing of ModBus cables and power cables and use orthogonal
crossing if crossing must be used.
● The shield layer of cables should be connected to protected ground or
to equipment ground if the equipment ground has already been connec‐
ted to protected ground. Do not directly ground any point of the RS485
network.
● In no circumstance should ground cables constitute a loop.
Bosch Rexroth AG DOK-RCON02-FV*********IB01-EN-P
Rexroth Frequency Converter Fv
190/219
Communication Protocols