Value Update With Data Transfer From Logo! To Knx - Siemens LOGO! CMK2000 Operating Instructions Manual

8.5.4

Value update with data transfer from LOGO! to KNX

In order to optimize the bus load (message frame rate) on KNX, it is possible to activate
sending of values when they change. Each KNX channel can be parameterized such that a
KNX message frame is only sent upon certain changes in value. On the other hand, values
can also be sent cyclically in order to synchronize smaller changes in value which are not
time-critical.
Image 8-2
Sending
For each channel you can define the cycle in which the value is to be sent to KNX. Criteria
for updating on the KNX bus can be a change in value on the one hand or the reaching of a
parameterized cycle time on the other. The following options are available for updating a
value:
Cyclic
If value has changed
Cyclic and if value has
changed
Note
• Digital values are not affected by this parameterization of the value update. Digital values
are automatically transferred to the KNX bus upon each change in value.
• A change in value can only be reliably detected if it is present for longer than the update
rate at which the values are read out from the LOGO! by the CMK2000.
• The minimum change in value refers to the LOGO! range of values.
CMK2000
Operating Instructions, 11/2015, A5E34877550B/001
Value update on the KNX bus
Parameter
Time value is parameterized
(Time unit: minute)
Difference in values is parameterized
(Value without unit)
Time value and difference in values
are parameterized.
The transfer is made as soon as a
criterion is satisfied. The cycle time is
restarted following the transfer of a
value.
Configuring and commissioning using ETS
8.5 Parameter assignments for the KNX channels
Range of values
1...240
•
1 byte: 1...255
•
2 bytes: 1...65535
•
4 bytes: 1...4294967295
•
The ranges apply as for cyclic / if
value has changed.
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