5.5. Installation of misc. connections5.5.1. RS 485 Bus ConnectionOne or more frequency converters can be con-nected to a control (or master) using theRS485 standardized interface. Terminal 68 isconnected to the P signal (TX+, RX+), whileterminal 69 is connected to the N signal(TX-,RX-).If more than one frequency converter is con-nected to a master, use parallel connections.In order to avoid potential equalizing currents in the screen, earth the cable screen via terminal61, which is connected to the frame via an RC-link.Bus terminationThe RS485 bus must be terminated by a resistor network at both ends. For this purpose, set switchS801 on the control card for "ON".For more information, see the paragraphSwitches S201, S202, and S801.NB!Communication protocol must be set to FC MC par. 8-30.5.5.2. How to Connect a PC to the FC 100To control or program the frequency converter from a PC, install the MCT 10 Set-up Software.The PC is connected via a standard (host/device) USB cable, or via the RS-485 interface as shownin the FC 100 Design Guide chapter How to Install > Installation of misc. connections.NB!The USB connection is galvanically isolated from the supply voltage (PELV) and otherhigh-voltage terminals. The USB connection is connected to protection earth on thefrequency converter. Use only isolated laptop as PC connection to the USB connectoron the VLT HVAC Drive.VLT® HVAC Drive Design Guide 5. How to InstallMG.11.B2.02 - VLT® is a registered Danfoss trademark 1035
