Decentral Solutions
Programming, FCD
300
■
Data Character (byte)
The structure of data blocks depends on the type
of telegram. There are three types of telegram,
and the type of telegram applies for both control
telegrams (master
slave) and response telegrams
(slave
master). The three types of telegram are:
-
Parameter block, 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.
-
The process block is made up of a data block
of four bytes (2 words) and contains:
-
Control word and reference value
-
Status word and present output frequency
(from slave to master)
-
Text block, which is used to read or write
texts via the data block.
Parameter commands and responses (AK).
Bits no. 12-15 are used to transfer parameter
commands from master to slave and the slave
’
s
processed responses 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
Response slave
master
Bit no.
Response
15 14 13 12
0
0
0
0
No response
0
0
0
1
Parameter value transferred
(word)
0
0
1
0
Parameter value transferred
(double word)
0
1
1
1
Command cannot be performed
1
1
1
1
Text transferred
If the command cannot be performed the slave
sends this response: 0111
Command cannot
be performed
and gives the following fault report
in the parameter value (PWE):
MG.90.F2.22 - VLT is a registered Danfoss trademark
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