Network Configuration - Danfoss FC 300 Design Manual

FC 300 Design Guide
The FC protocol, also referred to as FC bus or Standard bus, is the Danfoss Drives standard serial
communication bus. It defines an access technique according to the master-slave principle for
communications via a serial bus.
One master and a maximum of 126 slaves can be connected to the bus. The individual slaves are
selected by the master via an address character in the telegram. A slave itself can never transmit
without first being requested to do so, and direct message transfer between the individual slaves
is not possible. Communications occur in the half-duplex mode.
The master function cannot be transferred to another node (single-master system).
The physical layer is RS-485, thus utilizing the RS-485 port built into the adjustable frequency
drive. The FC protocol supports different telegram formats; a short format of 8 bytes for process
data, and a long format of 16 bytes that also includes a parameter channel. A third telegram format
is used for texts.

9.3. Network Configuration

9.3.1. FC 300 Adjustable Frequency Drive Set-up
Set the following parameters to enable the FC protocol for the FC 300.
Parameter
ber
8-30
8-31
8-32
8-33
NOTE
Relevant national and local regulations, for example, regarding protective ground
connection, must be observed. The RS-485 communication cable must be kept away
from motor and brake resistor cables to avoid coupling of high frequency noise from
one cable to another. Normally a distance of 200 mm (8 inches) is sufficient, but
keeping the greatest possible distance between the cables is generally recommen-
ded, especially where cables run in parallel over long distances. When crossing is
unavoidable, the RS-485 cable must cross motor and brake resistor cables at an
angle of 90 degrees.
Num- Parameter name
Protocol
Address
Baud Rate
Parity/Stop bits
MG.33.B9.22 - VLT ® is a registered Danfoss trademark.
9. RS-485 Installation and Set-up
Setting
FC
1 - 126
2400 - 115200
Even parity, 1 stop bit (default)
9
167