Specifications

Bit no. Parameter command
15 14 13 12
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
Table 7.4 Parameter Commands, Master to Slave
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
Table 7.5 Response, Slave to Master
If the command cannot be performed, the slave sends the response, 0111 Command cannot be performed, and issues the
following fault report in the parameter value (PWE):
PWE low (Hex) Fault Report
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
11 Data change in the defined parameter is not possible in the present mode. Certain parameters can only be
changed when the motor is turned off
82 There is no bus access to the defined parameter
83 Data change is not possible because factory setup is selected
Table 7.6 Faults
7.4.8 Parameter Number (PNU)
Bits no. 0-11 transfer parameter numbers. The function of
the relevant parameter is defined in the parameter
description in the Programming Guide.
7.4.9 Index (IND)
The index is used together with the parameter number to
read/write-access parameters with an index. The index
consists of 2 bytes, a low byte and a high byte.
Only the low byte is used as an index.
7.4.10 Parameter Value (PWE)
The parameter value block consists of 2 words (4 bytes),
and the value depends on the defined command (AK). The
master prompts for a parameter value when the PWE block
contains no value. To change a parameter value (write),
write the new value in the PWE block and send it from the
master to the slave.
When a slave responds to a parameter request (read
command), the present parameter value in the PWE block
is transferred and returned to the master. If a parameter
contains not a numerical value but several data options,
select the data value by entering the value in the PWE
block. Serial communication is only capable of reading
parameters containing data type 9 (text string).
Installation and Set-up VLT® HVAC Drive FC 102 Design Guide
MG16C102 - Rev. 2013-08-20 167
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