Supported Data Types; Conversion; Process Words (Pcd); Examples - Danfoss VLT AutomationDrive FC 301 Design Manual

RS-485 Installation and Set...
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".
Some parameters contain text that can be written to 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".
PKE
Read text Fx xx
Write text Fx xx
Illustration 12.11 Text via PWE Block

12.7.11 Supported Data Types

Unsigned means that there is no operational sign in the
telegram.
Data types
3
4
5
6
7
9
10
13
33
35
Table 12.7 Supported Data Types

12.7.12 Conversion

The various attributes of each parameter are displayed in
factory setting. 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
®
VLT AutomationDrive FC 301/FC 302 Design Guide, 0.25-75 kW
IND PWE PWE
high low
04 00
05 00
Description
Integer 16
Integer 32
Unsigned 8
Unsigned 16
Unsigned 32
Text string
Byte string
Time difference
Reserved
Bit sequence
MG33BF02 - Rev. 2013-12-20
value transferred is multiplied by 0.1. The value 100 is
therefore read 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
Conversion index
100
75
74
67
6
5
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
Table 12.8 Conversion Table

12.7.13 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 12.9 Process Words (PCD)
12.8 Examples

12.8.1 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
Conversion factor
1000000
100000
10000
1000
100
10
1
0.1
0.01
0.001
0.0001
0.00001
0.000001
0.0000001
PCD 2
Reference-value
Present output
frequency
181
12 12