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VLT
®
8000 AQUA
Programming
■
Data character (byte)
The build-up of data blocks depends on the type of
telegram. There are three types of telegram and the
telegram type applies to both control telegram (master
⇒
slave) and reply telegram (slave
⇒
master). The
three types of telegram are the following:
1. Parameter block, used for transferring parameters
between master and slave. The data block has 12
bytes (6 words) and also contains the process block.
2. Process block, built up as a data block with
four bytes (2 words), covering:
- Control word and reference value (from
master to slave)
- Status word and present output frequency
(from slave to master).
3. Text block, used for reading or writing texts
via the data block.
1. Parameter bytes
Parameter commands and replies (AK) Bits
no. 12-15 are used for transferring parameter
commands from master to slave and the slave
’
s
processed reply back to the master.
Parameter commands
→
master slave:
Bit no.
15 14 13 12 Parameter command
0
0
0
0
No command
0
0
0
1
Read parameter value
0
0
1
0
Write parameter value in RAM
(word)
0
0
1
1
Write parameter value in RAM
(double word)
1
1
0
1
Write parameter value in RAM
and EEPROM (double word)
1
1
1
0
Write parameter value in RAM
and EEPROM (word)
1
1
1
1
Read/write text
Reply slave
→
master:
Bit no.
15 14 13 12 Reply
0
0
0
0
No reply
0
0
0
1
Parameter value transferred
(word)
0
0
1
0
Parameter value transferred
(double word)
0
1
1
1
Command cannot be executed
1
1
1
1
Text transferred
MG.83.A2.02 - VLT is a registered Danfoss trademark
151