Specifications

2. Address format 1-126:
Bit 7 = 1 (address format 1-126 active)
Bit 0-6 = frequency converter address 1-126
Bit 0-6 = 0 Broadcast
The follower returns the address byte unchanged to the
master in the response telegram.
8.4.5 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.
8.4.6 The Data Field
The structure of data blocks depends on the type of telegram. There are 3 telegram types, and the type applies for both
control telegrams (master⇒follower) and response telegrams (follower⇒master).
The 3 types of telegram are:
Process block (PCD)
The PCD is made up of a data block of 4 bytes (2 words) and contains:
•
Control word and reference value (from master to follower)
•
Status word and present output frequency (from follower to master)
ADRLGESTX PCD1 PCD2 BCC
130BA269.10
Illustration 8.7 Process Block
Parameter block
The parameter block is used to transfer parameters between master and follower. The data block is made up of 12 bytes (6
words) and also contains the process block.
PKE INDADRLGESTX PCD1 PCD2 BCC
130BA271.10
PWE
high
PWE
low
Illustration 8.8 Parameter Block
Text block
The text block is used to read or write texts via the data block.
PKE IND
130BA270.10
ADRLGESTX PCD1 PCD2 BCCCh1 Ch2 Chn
Illustration 8.9 Text Block
Installation and Set-up Design Guide
MG11BC02 Danfoss A/S © Rev. 06/2014 All rights reserved. 133
8 8