Parameter Interface In Write.request - Danfoss InterBus-S Handbuch

Parameter interface in
Write.Request
The parameter interface (PCV) of the VLT
5000 contains a total of 4 words. This
enables reading and writing of parame-
ters, reading of arrays, writing, etc.
The parameter interface can be detailed
as follows:
1. Word (Parameter-Identification-Value,
PCA); in the lower 11 bits (bits 0..10) enter
the parameter number, in the upper four
bits (bits 12..15) select the desired action.
2. Word (Index/Subindex, IND); the byte
"Index" is only used if wanting to use
elements of an array. In this case, enter
the index of the element in question. In
normal parameter actions, this byte is not
used. The byte subindex is intended for
subsequent extensions and is not used at
this point.
3. + 4. Word (Parameter Value, PVA); in
the case of write action, this is where the
value of the selected parameter is ente-
red. The third word is the High-Word; the
fourth word is the Low-Word. The third
word is only used if parameter values
above 65535 are to be transmitted.
Since values are not transmitted in
comma format, each parameter value
must be multiplied by a factor. The para-
meter factor in each case can be seen
from the manual for the PROFIBUS Option
Card.
6
Gateway InterBus-S
Example:
In VLT ® 5000, with bus address 2, the
®
parameter 202 maximum frequency is to
be changed to 80 Hz,
PCA: 20CA
Parameter CA hex = 202
Action 2 = Change parameter value
IND: 0000
no Subindex
no Index
PVA: 0000 0320
Parameter value_low =
320 hex = 800 = 80.0 x Factor 10
Parameter value_high = 0
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