The Data Field - Danfoss VLT AutomationDrive FC 300 Design Manual

RS-485 Installation and Set...

10.7.6 The Data Field

The structure of data blocks depends on the type of message. There are three 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 10.6 PCD
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.
STX
10 10
Figure 10.7 Parameter block
Text block
The text block is used to read or write texts via the data block.
STX
Figure 10.8 Text Block
270
LGE ADR
LGE ADR PKE
LGE ADR PKE IND
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
Design Guide
PCD1
PWE PWE
IND
high low
Ch1 Ch2
PCD2
PCD1 PCD2
Chn PCD1 PCD2
BCC
BCC
BCC
MG34S222