Siemens Climatix S300 HRV - Mapping Application Parameters to Modbus Registers

6.3.6 Mapping application parameters to Modbus registers
Applications parameters support either extended or basic read/write mechanism.
Extended read/write
The following
extended mapping
examples illustrate:
● BA analog output object represented on Modbus by 4 holding registers
● BA analog input object represented on Modbus by 4 input registers
● Data item size is 4 in both cases
Example of an analog input object (extended read):
Input register address Data item structure
X
X+1
Present value
X+2 Status flags Voidfield(=0:0)
X+3 Reliability
Example of an analog output or value object (extended read/write):
Holding register address Data item structure
X
X+1
Present value
X+2 Status Flags Cmd(=Ready) Priority
X+3 Reliability
Register
address
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
x
Present value
x+1
x+2 r(0) r(0) r(0) r(0)
Status flags Cmd Priority
x+3
Reliability
Data item structure for 32bit data and Mapping=Extended
Engineering of communicative devices
Modbus slave
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