Fieldbus Scale - Kruger Ecowatt Drive K120 Series Operation Manual

Ecowatt ® Drive K120 series
Eight high-order
bits of code
01
Note: A device code consists of 16 bits, with eight high-order bits and eight low-order
bits. Eight high-order bits indicates the motor series, and eight low-order bits indicates
the derivative model.

7.4.3 Fieldbus scale

In practical applications, communication data is represented in the hexadecimal form,
but hexadecimal values cannot represent decimals. For example, 50.12 Hz cannot be
represented in the hexadecimal form. In such cases, we can multiply 50.12 by 100 to
obtain an integer 5012, and then 50.12 can be represented as 1394H (5012 in the decimal
form) in the hexadecimal form.
In the process of multiplying a non-integer by a multiple to obtain an integer, the
multiple is referred to as a fieldbus scale.
The fieldbus scale depends on the number of decimals in the value specified in
"Description" or "Default" of the function parameter list. If there are n decimals in the
value (for example, n=1), the fieldbus scale m is the nth-power of 10. Take the following
table as an example, m is 10.
Function
Name
code
Wake-up-fro
P01.20 m-sleep
delay
Restart after
P01.21
power-off
The value specified in "Setting range" or "Default" contains one decimal, so the fieldbus
scale is 10. If the value received by the upper computer is 50, the value of
"Wake-up-from-sleep delay" of the VFD is 5.0 (5.0=50/10).
To set the "Wake-up-from-sleep delay" to 5.0s through Modbus communication, you
need first to multiply 5.0 by 10 according to the scale to obtain an integer 50, that is, 32H
in the hexadecimal form, and then transmit the following write command:
address
Eight low-order
Meaning
bits of code
Kruger
0.0–3600.0s (valid when P01.19 is 2)
0: Disable
1: Enable
VFD Write
command
06 K120 vector VFD
Description
Parameter
Data number
address
-140-
Communication protocol
Meaning
Default
0.0s
0
CRC check
Modify
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