Fc Protocol Examples - Danfoss VLT Refrigeration Drive FC 103 Design Manual

System Integration
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 fieldbus. 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 3.51 Text via PWE Block
3.9.7.11 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 3.29 Supported Data Types
3.9.7.12 Conversion
The various attributes of each parameter are shown in
factory setting. Parameter values are transferred as whole
numbers only. Conversion factors are therefore used to
transfer decimals.
Parameter 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 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
MG16G202
Design Guide
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
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3.9.7.13 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⇒slave control word) Reference value
Control telegram (slave⇒master status word)
Table 3.30 Process Words (PCD)

3.9.8 FC Protocol Examples

3.9.8.1 Writing a Parameter Value
Change parameter 4-14 Motor Speed High Limit [Hz] to 100
Hz.
Write the data in EEPROM.
PKE=E19E hex - Write single word in parameter 4-14 Motor
Speed High Limit [Hz].
IND=0000 hex
PWEHIGH=0000 hex
PWELOW=03E8 hex - Data value 1000, corresponding to
100 Hz, see chapter 3.9.7.12 Conversion.
The telegram looks like this:
E19E H 0000 H 0000
PKE IND PWE
Illustration 3.52 Write Data in EEPROM
NOTICE
Parameter 4-14 Motor Speed High Limit [Hz] is a single
word, and the parameter command for write in EEPROM
is E. Parameter number 4-14 is 19E in hexadecimal.
The response from the slave to the master is:
119E H 0000 H 0000
PWE
PKE IND
Illustration 3.53 Response from Slave
3.9.8.2 Reading a Parameter Value
Read the value in parameter 3-41 Ramp 1 Ramp Up Time.
PKE=1155 hex - Read parameter value in
parameter 3-41 Ramp 1 Ramp Up Time.
IND=0000 hex
PWEHIGH=0000 hex
PWELOW=0000 hex
PCD 2
Present output
frequency
H 03E8 H
PWE
high low
H 03E8 H
PWE
low
high
77
3 3