Danfoss VLT CDS 803, Design Manual

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7.4.7 The PKE Field
The PKE field contains 2 subfields:
•
Parameter command and response (AK)
•
Parameter number (PNU)
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
130BB918.10
PKE IND PWE
high
PWE
low
AK PNU
Par
amet
er
commands and r
eplies
Par
amet
er
number
Illustration 7.9 PKE Field
Bits 12–15 transfer parameter commands from master to
slave and return processed slave responses to the master.
Parameter commands master
⇒
slave
Bit number 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 text.
Table 7.5 Parameter Commands
Response slave
⇒
master
Bit number 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 7.6 Response
If the command cannot be performed, the slave sends this
response
0111 Command cannot be performed and issues
the following fault report in Table 7.7 .
Fault code FC specification
0 Illegal parameter number.
1 Parameter cannot be changed.
2 Upper or lower limit is exceeded.
3 Subindex is corrupted.
4 No array.
5 Wrong data type.
6 Not used.
7 Not used.
9 Description element is not available.
11 No parameter write access.
15 No text available.
17 Not applicable while running.
18 Other errors.
100 –
>100 –
130 No bus access for this parameter.
131 Write to factory set-up is not possible.
132 No LCP access.
252 Unknown viewer.
253 Request is not supported.
254 Unknown attribute.
255 No error.
Table 7.7 Slave Report
7.4.8 Parameter Number (PNU)
Bit numbers 0–11 transfer parameter numbers. The
function of the relevant parameter is defined in the
parameter description in
chapter 6 How to Program .
7.4.9 Index (IND)
The index is used with the parameter number to read/
write access parameters with an index, for example,
parameter 15-30 Alarm Log: Error Code . 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 from the
master to the slave.
RS485 Installation and Set-...
VLT
®
Compressor Drive CDS 803
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