Danfoss FC 300 Design Manual page 274

FC 300 Design Guide
How to Program
Parameter number (PNU)
Bits no. 0-10 transfers parameter numbers. The relevant parameter's function is defined in
the parameter description in the chapter How to Program.
Index
Index is used together with the parameter number
to read/write-access parameters with an index,
e.g. par. 15-30 Error code. The index consists
of 2 bytes - one lowbyte and one highbyte. Only
the lowbyte is used as an index.
Example - Index:
The first error code (index [1]) in par. 15-30
Error Code must be read.
PKE = 15 FA Hex (read par. 15-30 Error Code.)
IND = 0001 Hex - Index no. 1.
The adjustable frequency drive responds in the
parameter value block (PWE) with a fault code
value from 1 - 99. See Summary of Warnings
and Alarms to identify the fault code.
Parameter value (PWE)
The parameter value block consists of 2
words (4 bytes), and the value depends on
the defined command (AK). If the master
prompts for a parameter value, the PWE block
does not contain a value.
If you want the master to change a parameter value (write), the new value is written
in the PWE block and sent to the slave.
If the slave 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, e.g. par. -001 Language
where [0] corresponds to English, and [4] corresponds to Danish, select the data value by entering
the value in the PWE block. See Example - Selecting a data value.
Via serial communication, it is only possible to read parameters that have data type 9 (text
string). Par. 15-40 to 15-33 Drive Identification is data type 9. For example, you can read
the unit size and mains voltage range in par. 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 telegram's second byte, known as LGE.
To read a text via the PWE block, set the parameter command (AK) to "F" Hex.
The index character indicates if the command is
read or write. In a read command, the index
must have the shown format:
default setting ( ) display text [ ] value for use in communication via serial communication port
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