ONICON System-10 MODBUS - Manual (Page 26)

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System-10-MOD Network Interface Installation Guide 05/14 - 0653-10 / 18321
Page 26
2.3 TOTALIZATION, RESETTING TOOLS AND OVER-RANGE & ROLLOVER
A. Integer Register Totalization
Holding registers 40026 through 40061 are integer registers that provide totalized energy,
volume and mass flow data in a variety of engineering units. The registers are organized
into pairs or groups of three.
The first (low order) register is limited to a range of 0 – 999. This register rolls over to zero
when the total value reaches 1,000. If the registers are in a group of three, the second
register (middle order) is also limited to a range of 0 – 999. This register also rolls over
when the register value reaches 1,000.
The second, or in the case of groups of three, third, (high order) register is scaled such that
the smallest incremental value indicated is 1,000 times greater than the preceeding
register. An example of this is shown below.
Example - A group of 3 registers
Register Engineering units & Scaling Current Value
40026 kBtu (Btu x 1,000) 00500
40027 MBtu (Btu x 1,000,000) 00015
40028 GBtu (Btu x 1,000,000,000) 00111
Low order + middle order + high order = Btu Total = 111,015,500,000
or
kBtu Total = 111,015,500
Registers 40062 and 40063 provide totalization for the optional auxiliary pulse input
option of the System-10 BTU Meter. There are no engineering units associated with these
registers.
B. Floating Point Totalization
Registers 41003 through 41064 provide energy, volume and mass flow data in 32 bit single
precision floating point format. The registers are organized into pairs. Each pair must be
concatenated according to IEEE 754.
Register order: Most significant first, least significant second.
Word order: Most significant value first, least significant value second.
Byte order within each word: Most significant byte first.
Bit order within each byte: Most significant bit first.
Registers 41063 and 41064 provide totalization for the optional auxiliary pulse input
option of the System-10 BTU Meter. There are no engineering units associated with these
registers.