8.4.7 The PKE Field
The PKE field contains 2 subfields: Parameter command
and response (AK) and 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 8.9 PKE Field
Bits no. 12-15 transfer parameter commands from master
to follower and return processed follower responses to the
master.
Parameter commands master
⇒
follower
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 text
Table 8.5 Parameter Commands
Response follower
⇒
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
Table 8.6 Response
If the command cannot be performed, the follower sends
this response:
0111 Command cannot be performed
- and issues the following fault report in the parameter
value:
Error code
FC Specification
0
Illegal Parameter Number
1
Parameter cannot be changed.
2
Upper or lower limit exceeded
3
Subindex corrupted
4
No Array
5
Wrong Data Type
6
Not used
7
Not used
9
Description element not available
11
No parameter write access
15
No text available
17
Not while Running
18
Other error
100
>100
130
No bus access for this parameter
131
Write to factory set-up not possible
132
No LCP access
252
Unknown viewer
253
Request not supported
254
Unknown attribute
255
No error
Table 8.7 Follower Report
8.4.8 Parameter Number (PNU)
Bits no. 0-11 transfer parameter numbers. The function of
the relevant parameter is defined in the parameter
description in the
VLT
®
Micro Drive FC 51 Programming
Guide
.
8.4.9 Index (IND)
The index is used with the parameter number to read/
write-access parameters with an index, for example,
15-30 Alarm Log: Error Code
. The index consists of 2 bytes;
a low byte, and a high byte. Index (IND)
Only the low byte is used as an index.
8.4.10 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),
RS-485 Installation and Set...
VLT
®
Micro Drive FC 51 Design Guide
MG02K302 - Rev. 2013-12-03
69
8
8