Users Manual

Operating Instructions Smart Weather Sensor
G. Lufft Mess- und Regeltechnik GmbH, Fellbach, Germany 137
19.7.3.2 Function 0x03 Read Holding Registers
The Holding Registers are used to make a selected set of adjustable parameters available
for Modbus access. As for the measurement values the parameters are mapped to 16bit
integers.
Reg.
No.
Reg.
Addr
Function
Values
Scale
1
0
Local Altitude
Altitude in m, for calculation of relative air pressure
Value range -100 … 5000
1.0
2
1
Deviation
Local deviation for the correction of compass heading.
Value range -3599 … 3599
(equalling -359.9° … +359.9°)
10.0
3
2
Averaging Interval
TFF
Interval for averaging and min/max evaluation in minutes
Value range 1 … 10
1.0
4
3
Averaging Interval
Air Pressure
Interval for averaging and min/max evaluation in minutes
Value range 1 … 10
1.0
5
4
Averaging Interval
Wind
Interval for averaging and min/max evaluation in minutes
Value range 1 … 10
1.0
6
5
Averaging Interval
Global Radiation
Interval for averaging and min/max evaluation in minutes
Value range 1 … 10
1.0
7
6
Heating Mode
High-Byte: Heating Mode Wind
Low-Byte Heating Mode R2S
Value range of each byte 0 … 3
(Details s. 10.5)
8
7
Reset abs. Rain
(Function only when writing to the register, reading will
give 0 always)
9
8
Device reset
(Function only when writing to the register, reading will
give 0 always)
Heating Modes (see 10.5):
Automatic 0
Mode 1 1
Off 2
Eco 1 3
19.7.3.3 Function 0x06 Write Holding Register, 0x10 Write Multiple Registers
By writing into the holding registers selected parameters of the Smart Weather Sensor can
be adjusted through Modbus.
Register assignment see19.7.3.2
Local altitude, compass deviation and averaging intervals are set by writing the new values
into the related registers. Depending on the selected register the value has to be scaled by
the factor given in the table:
Example: for compass deviation the table shows a scaling factor of 10.0. If the deviation is
4.8° a value of 48 shall be written into register 2 (reg.addr. 1).
The transmitted values will be checked for plausibility. Illegal values will not be accepted and
cause a Modbus exception.
When writing the value 0x3247 (12871d) to register no. 8 (reg. addr. 7) the stored absolute
rain amount will be set to 0. Subsequently a device reset will be initiated.
When writing the value 0x3247 (12871d) to register no. 9 (reg. addr. 8) a device reset will be
initiated.
Setting of the heating mode:
The wind sensor heating mode is coded into the high byte of the 16bit register no. 7, the
precipitation sensor heating mode into the low byte of this register
Example :
Heating mode wind: Mode 1 (Code 1)
Heating mode precipitation: Off (Code 2)
Write to register 7 (reg. addr. 6): 0x0102 (=258d)