Danfoss VLT Refrigeration Drive FC 103 Design Manual page 78

System Integration
3.9.7.7 The PKE Field
The PKE field contains 2 subfields:
•
Parameter command and response AK.
•
Parameter number PNU.
3 3
AK
15 14 13 12 11 10 9
Illustration 3.50 PKE Field
Bits numbers 12–15 transfer parameter commands from
master to slave and return processed slave responses to
the master.
Bit number
15 14 13
0 0 0
0 0 0
0 0 1
0 0 1
1 1 0
1 1 1
1 1 1
Table 3.26 Parameter Commands Master⇒Slave
Bit number
15 14 13
0 0 0
0 0 0
0 0 1
0 1 1
1 1 1
Table 3.27 Response Slave⇒Master
If the command cannot be performed, the slave sends this
response:
0111 Command cannot be performed
- and issues a fault report (see Table 3.28) in the parameter
value (PWE):
76
VLT
PKE IND PWE
high
PNU
8 7 6 5 4 3 2 1
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.
Danfoss A/S © 08/2015 All rights reserved.
®
Refrigeration Drive FC 103
PWE low
(hex)
0
1
2
3
4
PWE
low
5
11
0
82
83
Table 3.28 Parameter Value Fault Report
3.9.7.8 Parameter Number (PNU)
Bits number 0–11 transfer parameter numbers. The
function of the relevant parameter is defined in the
parameter description in the programming guide.
3.9.7.9 Index (IND)
The index is used together 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.
3.9.7.10 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 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
does not contain a numerical value, but several data
options, for example parameter 0-01 Language where [0] is
English, and [4] is Danish, 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).
Parameter 15-40 FC Type to parameter 15-53 Power Card
Serial Number contain data type 9.
For example, read the unit size and mains voltage range in
parameter 15-40 FC Type. When a text string is transferred
(read), the length of the telegram is variable, and the texts
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
MG16G202