BLH NOBEL G4-DT, Technical Manual

Page: 135 / 194

G4 Multi Channel Weighing Instrument
6-29
Float values
The type of float values used in the communication is selected in the set-up for the
different communication interfaces.
Values stored as standard IEEE 32 bit float values. Each value has two registers
assigned to it. To read/write a float value an even number of Modbus registers, starting
at an even address, must be read/written each time. The float values are stored in two
different register orders.
Some devices may transfer the values with the high order bits in the first register and
the low order bits in the second register. Other devices may invert the register order.
Modicon float: For true Modicon PLC’s.
Float: Many third party controllers that support Modicon protocol use the float
format where all bytes are written out in order to one 32 bit register, as
opposed to Modicon float which uses 2 consecutive 16 bit registers.
When float registers representing bits are read, the bits set are returned as a float value.
For example if bit 4 is set the value 16.0 is returned as a float value, and if
both bit 0 and bit 4 are set the value 17.0 is returned as a float value.
To use the value it’s a good choice to convert it to an unsigned integer where
the bits can be compared.