7.4.11 Data Types Supported by the
Adjustable Frequency Drive
Unsigned means that there is no operational sign in the
telegram.
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 7.7
7.4.12 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:
0s --> conversion index 0
0.00s --> conversion index -2
0ms --> conversion index -3
0.00ms --> conversion index -5
Conversion index
Conversion factor
100
75
74
67
6
1000000
5
100000
4
10000
3
1000
2
100
1
10
0
1
-1
0.1
-2
0.01
-3
0.001
-4
0.0001
-5
0.00001
-6
0.000001
-7
0.0000001
Table 7.8 Conversion Table
7.4.13 Process Words (PCD)
The block of process words is divided into two blocks of
16 bits, which always occur in the defined sequence.
PCD 1
PCD 2
Control message (master
⇒
slave Control
word)
Reference value
Control message (slave
⇒
master) Status
word
Present output
frequency
Table 7.9
7.5 Examples
7.5.1 Writing a Parameter Value
Change
4-14 Motor Speed High Limit [Hz]
to 100 Hz.
Write the data in EEPROM.
PKE = E19E Hex - Write single word in
4-14 Motor Speed
High Limit [Hz]
IND = 0000 Hex
PWEHIGH = 0000 Hex
PWELOW = 03E8 Hex - Data value 1000, corresponding to
100 Hz, see Conversion.
The telegram will look like this:
RS-485 Installation and Set...
VLT
®
HVAC Drive Design Guide
MG11BB22 - VLT
®
is a registered Danfoss trademark
7-9
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