Siemens Milltronics BW500 Operating Lnstructions page 105

Writing Parameters
To set parameters through Modbus follow these 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 BW500 and BW500/L
to interpret the value correctly.
Format Register:
Bits Values
1 - 8 0 - 2
9 - 11 0 - 7
12 0/1
13 0/1
14 0/1
15 0/1
16
The bits listed above are in order from least to most significant:
16 15 14
e.g. to format the output value so that it is shown with two decimal places shifted to the
left the format bits would look like this:
16 15 14
0 0 0
The value sent to the BW500 and BW500/L is 0001001000000000 binary or 4608 decimal.
The value 4608 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. Bits 9 to 11 indicate
the number of places by which the decimal is to be shifted. Bit 12 indicates the direction
by which the decimal point is shifted, left or right. For example, if the decimal offset (value
of bits 9 to 11) is '2' and the shift (value of bit 12 is) '0' , then the decimal point is shifted two
places to the right.
7ML19985DK05Milltronics BW500 and BW500/L - OPERATING INSTRUCTIONS
Error Code
decimal offset
decimal shift, Right (0) or Left (1)
Numeric format: Fixed (0) or FLoat (1)
Read or Write of data, Read (0), Write (1)
Word order: Most Significant word first (0), Least Significant Word
first (1)
Reserved
13 12 11 10
13 12 11 10
1 0 0 1
Description
9 8 7 6
9 8 7 6
0 0 0 0
5 4 3 2
5 4 3 2
0 0 0 0
Page 99
1
1
0