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10.7.10 Parameter Value (PWE)
The parameter value block consists of two 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,
for example,
0-01 Language
[0] English
, and
[4] 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).
15-40 FC Type
to
15-53 Power Card Serial Number
contain
data type 9.
For example, read the unit size and AC line voltage range
in
15-40 FC Type
. When a text string is transferred (read),
the length of the telegram is variable, and the texts are of
different lengths. The message length is defined in the
second byte of the message, LGE. When using text transfer,
the index character indicates whether it is a read or a write
command.
To read a text via the PWE block, set the parameter
command (AK) to ’F’ Hex. The index character high-byte
must be “4.”
Some parameters contain text that can be written via the
serial bus. To write a text via the PWE block, set the
parameter command (AK) to ’F’ Hex. The index characters
high-byte must be “5.”
PWE
high
PWE
low
Read text
Write text
130BA275.10
PKE
IND
Fx xx
04 00
Fx xx
05 00
Figure 10.10 PWE
10.7.11 Data Types Supported
Unsigned means that there is no operational sign in the
message.
Data types
Description
3
Integer 16
4
Integer 32
5
Unsigned 8
6
Unsigned 16
7
Unsigned 32
9
Text string
10
Byte string
13
Time difference
33
Reserved
35
Bit sequence
Table 10.6 Data Types Supported
10.7.12 Conversion
The various attributes of each parameter are displayed in
the section factory settings. Parameter values are
transferred as whole numbers only. Conversion factors are
therefore used to transfer decimals.
4-12 Motor Speed Low Limit [Hz]
has a conversion factor of
0.1.
To preset the minimum frequency to 10 Hz, transfer the
value 100. A conversion factor of 0.1 means that the value
transferred is multiplied by 0.1. The value 100 is thus
perceived as 10.0.
Examples:
0 s
⇒
conversion index 0
0.00 s
⇒
conversion index -2
0 ms
⇒
conversion index -3
0.00 ms
⇒
conversion index -5
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Design Guide
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