Contrec 515 FA01, Operation Manual

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Communications
515 FA01 - 29 August 2021 67
List of Data Registers
The following tables describe the addresses and meaning of the data
registers in the instrument. The registers are grouped in blocks that relate to
a particular function of the instrument. The data values are expressed in the
engineering units that were selected for the variables when the instrument
settings were configured.
Note: Conventional numbering of registers often starts from 1, therefore be
aware that “register 1” in this case has “address 0” and so on.
The data registers represent different data types as specified in the tables:
•
I - Integer, 2 bytes (Holding Register)
•
L - Long Integer, 4 bytes (2 registers)
•
P - Programmable Format, 4 bytes (2 registers)
The “Programmable Format” data type for 4-byte (2 registers) data values
can be set as either Floating Point or Long Integer via the “Data Type”
program item as described in
Communications on page 47.
The Floating Point variable is represented in IEEE-754 Floating Point
4-byte format and requires two 2-byte data registers:
This means that two data registers must be read or written to obtain, or
preset, one data value.
IEEE-754 Modicon Registers
1st byte low byte (register X)
2nd byte high byte (register X)
3rd byte low byte (register X+1)
4th byte high byte (register X+1)