Siemens Milltronics BW500 Operating Instructions Manual page 146

Communications
11.5 Modbus RTU/ASCII Protocol
Read/Write (R41,025 – R41,026) Total Decimal Places
Sets the number of decimal places (0-3) being read for Total 1, (words 41,016 and 41,017) and
Total 2, (words 41,018 and 41,019).
With 3 decimal places, the largest value that can be read is 2,147,483.648.
With 2 decimal places, the largest value that can be read is 21,474,836.48.
With 1 or 0 decimal places, the largest value that can be read is 100,000,000.
Although the word registers are limited to reading a maximum value as indicated above for the
defined number of decimal places, the overflow bits of Instrument_Status2 (Word 31) will only
reflect an overflow condition (Bits 1 and 2 set to 1) when the decimal place is set to 2 or 3.
When set to 2 or 3, the word registers will stop accumulating at the indicated values however,
the LUI will continue to totalize to a value of 100,000,000. Should this condition exist, prior to
resetting the totalizer registers, be sure to observe and record the totalized value as displayed
on the LUI. Not doing this could cause a reporting discrepancy in expected material totals within
the process.
Once the internal totalizer registers realize a value of 100,000,000, the internal registers will
perform a rollover, causing the display of the LUI to start from a value of 0. This will also cause
the Instrument_Status2 word bits to reset to 0.
Example: R41,025
Bits 0 and 1 are used to indicate the number of decimal places being read in Total 1: words 7
and 8.
Bit 15 is used to indicate if the decimal place is too large to read the total value correctly.
If three decimal places are being read in Total 1:
Bits 15
If three decimal places are being read in Total 1, and the value is too large to be read with three
decimal places:
Bits 15
I/O (R41,070 – 41,116)
The BW500 provides I/O in the form of:
● discrete inputs
● relay outputs
● mA inputs
● mA outputs
The standard BW500 provides only one mA output (0/4 – 20 mA). The inclusion of an optional
1)
mA I/O card provides two mA inputs (0/4 – 20 mA) and two additional mA outputs. The optional
mA I/O card is not available with BW500/L
144
14 13 12 11
0 0 1 0 0
14 13 12 11
1 0 1 0 0
1)
1)
10 9 8 7 6
1 0 0 0 0
10 9 8 7 6
1 0 0 0 0
Operating Instructions, 12/2016, A5E33482052-AD
5 4 3 2 1
0 0 0 0 1
5 4 3 2 1
0 0 0 0 1
BW500 and BW500/L
0
1
0
1