The Pke Field; Parameter Number (Pnu); Index (Ind); Parameter Value (Pwe) - Danfoss VLT AutomationDrive FC 301 Design Manual

RS-485 Installation and Set...

12.7.7 The PKE Field

The PKE field contains 2 sub-fields: Parameter command
and response AK, and Parameter number PNU:
AK
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Illustration 12.10 PKE Field
Bits no. 12-15 transfer parameter commands from master
to follower and return processed follower responses to the
master.
Bit no.
15 14 13
0 0 0
0 0 0
0 0 1
0 0 1
12 12
1 1 0
1 1 1
1 1 1
Table 12.4 Parameter Commands Master ⇒ Follower
Bit no.
15 14 13
0 0 0
0 0 0
0 0 1
0 1 1
1 1 1
Table 12.5 Response Follower⇒ Master
If the command cannot be performed, the follower sends
this response:
0111 Command cannot be performed
180
VLT
PKE IND
PWE
high
PNU
Parameter command
12
0 No command
1 Read parameter value
0 Write parameter value in RAM (word)
1 Write parameter value in RAM (double
word)
1 Write parameter value in RAM and
EEprom (double word)
0 Write parameter value in RAM and
EEprom (word)
1 Read/write text
Response
12
0 No response
1 Parameter value transferred (word)
0 Parameter value transferred (double
word)
1 Command cannot be performed
1 text transferred
®
AutomationDrive FC 301/FC 302 Design Guide, 0.25-75 kW
- and issues the following fault report in the parameter
value (PWE):
PWE low
(Hex)
0
PWE
low
1
2
3
4
5
11
82
83
Table 12.6 Parameter Value Fault Report

12.7.8 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.

12.7.9 Index (IND)

The index is used together with the parameter number to
read/write-access parameters with an index, e.g.
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.

12.7.10 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 follower.
When a follower 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,
e.g. 0-01 Language where [0] is English, and [4] is Danish,
select the data value by entering the value in the PWE
block. See Example - Selecting a data value. Serial
communication is only capable of reading parameters
containing data type 9 (text string).
MG33BF02 - Rev. 2013-12-20
Fault Report
The parameter number used does not exit
There is no write access to the defined parameter
Data value exceeds the parameter's limits
The sub index used does not exit
The parameter is not the array type
The data type does not match the defined
parameter
Data change in the defined parameter is not
possible in the frequency converter's present
mode. Certain parameters can only be changed
when the motor is turned off
There is no bus access to the defined parameter
Data change is not possible because factory set-
up is selected