Danfoss VLT FC 102 Operating Instructions Manual

Also see for VLT HVAC Drive FC 102: Operating instructions Service guide Programming guide Installation guide Installation guide

Contents

7.4.4 Frequency Converter Address (ADR)Two different address formats are used.The address range of the frequency converter is either 1-31 or 1-126.1. Address format 1-31:Bit 7 = 0 (address format 1-31 active)Bit 6 is not usedBit 5 = 1: Broadcast, address bits (0-4) are not usedBit 5 = 0: No BroadcastBit 0-4 = Frequency converter address 1-312. Address format 1-126:Bit 7 = 1 (address format 1-126 active)Bit 0-6 = Frequency converter address 1-126Bit 0-6 = 0 BroadcastThe slave returns the address byte unchanged to the master in the response telegram.7.4.5 Data Control Byte (BCC)The checksum is calculated as an XOR-function. Before the first byte in the telegram is received, the Calculated Checksum is 0.7.4.6 The Data FieldThe structure of data blocks depends on the type of telegram. There are three telegram types, and the type applies for both control telegrams (mas-ter=>slave) and response telegrams (slave=>master).The three types of telegram are:Process block (PCD):The PCD is made up of a data block of four bytes (2 words) and contains:- Control word and reference value (from master to slave)- Status word and present output frequency (from slave to master).Parameter block:The parameter block is used to transfer parameters between master and slave. The data block is made up of 12 bytes (6 words) and also contains theprocess block.7 RS-485 Installation and Set-upVLT HVAC Low Harmonic Drive Operating In-structions154 MG.16.A1.02 - VLT® is a registered Danfoss trademark7