7.4.6 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 (mas-
ter=>slave) and response messages (slave=>master).
The three types of message 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 the
process block.
Text block:
The text block is used to read or write texts via the data block.
VLT AQUA Low Harmonic Drive Instruction
Manual
7 RS-485 Installation and Set-up
MG.20.T1.22 - VLT
®
is a registered Danfoss trademark
7-7
7
To Next Page
Loading...
