Modbus - Siemens LMV27.100x2 Basic Documentation

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Building Technologies
No. Parameter
Operating mode building automation
0 = off
141

1 = Modbus

2 = reserved
Setback time in the event of communication breakdown
142
Setting values
0 = inactive
1...7200 s
Predefined output in the event of communication breakdown with building
automation
Setting values:
For modulating operation, the setting range is as follows:
0...19.9 = burner off
20...100 = 20...100% burner output (20 = low-fire position)
148
For multistage operation, use the following settings:
0 = burner OFF
P1...P3 = stage 1...stage 3
Invalid = no output predefined by the building automation system in the event
of communication breakdown
Default setting: Invalid
The factory settings of the parameters are shown on the Parameter list.
Note
For a detailed description of parameter 148, refer to chapter Default output via building
automation.
16.2 Modbus
With this type of bus protocol, the LMV27 operates as a slave on the Modbus and the
transmission mode used is RTU (Remote Terminal Unit).
For more detailed information, refer to the Modbus User Documentation (A7541).
No. Parameter
Device address for Modbus of LMV27
145
Setting values
1...247
Baud rate for Modbus
146 0 = 9600
1 = 19200
Setting of parity for Modbus communication
0 = none
147
1 = odd
2 = even
The factory settings of the parameters are shown on the parameter list.
Note
If bus communication breaks down, the mode, Modbus operating mode and predefined
target output must be rewritten.
Basic Documentation LMV27...
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CC1P7541en
17.12.2018