Fc Protocol Overview; Network Configuration - Danfoss FC 300 Design Manual

FC 300 Design Guide

FC Protocol Overview

The FC protocol, also referred to as FC bus or Standard bus, is the Danfoss Drives standard fieldbus. 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 frequency converter. 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.

Network Configuration

FC 300 Frequency Converter Set-up
Set the following parameters to enable the FC protocol for the FC 300.
Parameter Number
8-30
8-31
8-32
8-33
276
RS-485 Installation and Set-up
Parameter name Setting
Protocol FC
Address 1 - 126
Baud Rate 2400 - 115200
Parity/Stop bits Even parity, 1 stop bit (default)
MG.33.B7.02 - VLT is a registered Danfoss trademark