Danfoss VLT AutomationDrive FC 301 Series Design Manual page 194

RS-485 Installation and Set...
12.7.6 The Data Field
The structure of data blocks depends on the type of message. There are three message types, and the type applies for both
control messages (master⇒follower) and response messages (follower⇒master).
The three types of message are:
Process block (PCD)
The PCD is made up of a data block of four bytes (two words) and contains:
•
Control word and reference value (from master to follower)
•
Status word and present output frequency (from follower to master)
STX
Figure 12.7 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
(six words) and also contains the process block.
STX
Figure 12.8 Parameter Block
Text block
12 12
The text block is used to read or write texts via the data block.
STX
Figure 12.9 Text Block
192
LGE ADR
LGE ADR PKE
LGE ADR PKE IND
Design Guide
PCD1
PWE PWE
IND
high low
Ch1 Ch2
Rev. 2014-04-04 All rights reserved.
PCD2
PCD1 PCD2
Chn PCD1 PCD2
BCC
BCC
BCC
MG33BF22