KBR F144-MS-1V1C6-6RO-6DO-3, User Manual

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V2.01
25361_EDEBD
A0281-2320-1_EN
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Data point description for the Modbus protocol
14.1 Modbus commands supported
0x04 Read Input Registers
0x2B Read Device Identification
The multicomp F144-3 does not support broadcast commands. All Modbus commands
described are device-specific commands.
14.2 Data formats
(unsigned) short: 0x1234
Address +0 +1
Contents 0x12 0x34
Rule for byte sequence: MSB before LSB
(unsigned) long: 0x12345678
Address +0 +1 +2 +3
Contents 0x12 0x34 0x56 0x78
Rule for byte sequence: MSB before LSB
float:
Format Complies with the IEEE 754 standard
Representation 4 bytes
Accuracy 24 bits ( represent >7 decimal points)
Composition 24-bit mantissa; 8-bit exponent
Mantissa 24 bits (M) + 1 bit (S)
Exponent The MSB of the mantissa is always 1 => it is not saved separate-
ly! S = sign of the mantissa: S = 1 negative number; S = 0
positive number
Exponent 8 bits (0-255); is saved relative to 127, i.e. the current value of
the exponent is calculated by subtracting the number 127 from
the saved value.
Curr. exp. = saved exp value. – 127
=> range from 128 to -127!