Siemens HydroRanger 200 HMI, Operating Instructions Manual

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Communications
C.41 Single parameter access (SPA)
HydroRanger 200 HMI
348
Operating Instructions, 06/2018, A5E36281317-AC
C.41.3 Writing parameters
To set parameters through Modbus, do the following steps:
1.
Send the parameter, its primary index, and its secondary index (usually 0) to registers
40,090, 40,091, and 40,092.
2. Write the value to registers 40,096 and 40,097.
3. Write the desired format word to register 40,093 to enable the device to interpret the
value correctly.
C.41.4 Format register
Bits Values Description
1-8 0-2 Error Code
9-11 0-7 3-bit number representing decimal offset
12 0/1 Direction of offset (0 = right, 1 = left)
13 0/1 Numeric format: Fixed (0) or Float (1)
14 0/1 Read or Write of data, Read (0), Write (1)
15 0/1 Word order: Most Significant Word first (0), Least Significant Word
first (1)
16 Reserved
For example, to format the level reading so that it is shown in percent with two decimal
places shifted left, the format bits would look like this:
Bit
numbers 16 15 14 13 12 11 10 09 08 07 06 05 04 03 02 0
1
Bit
values 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0
Reserved
Most
significant
first Read Fixed
format Offset
direction to
right Decimal
offset of 2
No error code
The value sent to the device is 0001001000000000 binary or 512 decimal. The value 512 is
sent as an integer to register 40,093 to format the output words 40,094 and 40,095
accordingly.
If the numeric data type is set for integer and the value contains decimal places, they are
ignored. In this situation, use the decimal offset to ensure that you have an integer value and
then write your code to recognize and handle the decimal offset.