Data Types Supported By The Frequency Converter; Conversion; Process Words (Pcd); Examples - Danfoss FC 101 Design Manual

RS-485 Installation and Set...
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 several data options, e.g. 0-01 Language, 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 mains 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 telegram length is defined in the
second byte of the telegram (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".
7.4.11 Data Types Supported by the
Frequency Converter
Unsigned means that there is no operational sign in the
telegram.
Data types
3
4
5
6
7
9
Table 7.8 Data Types

7.4.12 Conversion

The various attributes of each parameter are displayed in
the chapter Parameter Lists in the Programming Guide.
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.
®
VLT HVAC Basic Drive FC 101 Design Guide
Description
Integer 16
Integer 32
Unsigned 8
Unsigned 16
Unsigned 32
Text string
MG18C502 - Rev. 2013-09-06
Conversion index
74
2
1
0
-1
-2
-3
-4
-5
Table 7.9 Conversion

7.4.13 Process Words (PCD)

The block of process words is divided into 2 blocks of 16
bits, which always occur in the defined sequence.
PCD 1
Control telegram (master⇒ follower Control
word)
Control telegram (follower⇒ master) Status
word
Table 7.10 Process Words (PCD)

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
7.4.12 Conversion.
The telegram looks like this:
E19E H 0000 H 0000
PKE IND PWE
Illustration 7.9 Telegram
Conversion factor
0.1
100
10
1
0.1
0.01
0.001
0.0001
0.00001
PCD 2
Reference-value
Present output
frequency
H 03E8 H
PWE
high low
85
7 7