Danfoss VLT 5000 Series, Руководство по эксплуатации

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VLT® 5000/ 5000 FLUX/ 6000 HVAC/
8000 AQUA PROFIBUS
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Parameter access
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Read/Write on VLT frequency converters
In an automation system, frequency converter
parameters can be accessed either from the
Process controller (i.e. PLC), or by various kinds
of HMI equipment. In order not to interfere access
from controllers and tools, the following should
be taken into consideration:
Parameter access in the drive is performed in
two logical parameter channels, which can be
individally programmed to access a certain parameter
setup via parameters 005 Programming Setup
and 970 Parameter setup selection.
This means, that before writing or reading to a
parameter in a certain frequency converter set-up
from a PLC, the parameter 970 must be set to the
desired set-up. For access from HMI equipment, the
access is controlled by parameter 005.
The figure below shows this behaviour, and the possible
sources of the two logical parameter channels.
VLT frequency converter
Access from process
control e.g. PLC:
- PCV channel (DP Vo)
- MSAC Master Class 1
Access from HMI:
- Local Control Panel
- FC standard interface
- MSAC Master class 2
Please note, that even though these two logical
parameter channels are separated, data conflict can
occour, if write on parameters is made from a HMI unit
into a set-up which is actively used by the frequency
converter or used by the process controller (e.g. PLC).
NB!:
For backward compability reasons the following
behaviour must be observed:
A Read or Write on parameter 970 via the MSAC
master class 2 connection will be accepted, but the
value will internally be read /written to parameter 005.
A Read or Write on parameter 005 via the process
controller channel will be accepted, but the value will
internally be read/written to parameter 970.
For parameter store, the following should be observed:
NB!:
A Write command to a frequency converter
parameter via the MSAC Master class 2
connection will be stored in RAM and in Non
Volatile Memory. Please note, that continuous writing
to frequency converter parameters via the MSAC
Master class 2 connection should be avoided in order
not to damage the Non Volatile Memory.
A Write command to a frequency converter parameter
via the Process Control channel will be stored in RAM
only. Store in Non Volatile Memory is possible by writing
a store command to parameter 971 Save data values,
which will result in store of the entire set-up in NVRAM.
The table below shows how data write from various
sources are stored in the frequency converter:
Data source RAM NVRAM
PCV channel (DP V0) Yes Store set-up by
parameter 971
MSAC Master Class 1 Yes Store set-up by
parameter 971
Local Control Panel Yes Yes
MCT 10 software via
FC interface
Yes Yes
MCT 10 software via
MSAC 2
Yes Yes
FC standard interface Yes Yes, by specific Write
command
MSAC Master Class 2 Yes Yes
MG.90.G1.02 - VLT is a registered Danfoss trademark
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