Danfoss VT2800 Series Design Manual page 110

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.
110
®
VLT 2800 Series
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 gi v es the following fault report
in the parameter value (PWE):
Response Fault report
(0111)
0 The parameter number used
does not exist
1 There is no write access to the
defined parameter
2 Data value exceeds
the parameter's limits
3 The sub index used
does not exist
4 The parameter is not the array type
5 The data type does not match the
defined parameter
17 Data change in the defined para-
meter is not possible in the
frequency
converter's present mode.
Certain parameters can only be
changed
when the motor is turned off
130 There is no bus access to the
defined parameter
131 Data change is not possible because
factory Setup is selected
MG.28.E9.02 - VLT is a registered Danfoss trademark