Calculation Rule Data Types; Floating Point Scaling - HBM QUANTUM X Bedienungsanleitung

Functional description
32
If the selected combination of start bit and length is
invalid, the CAN decoder will not change over to the
conversion rule and set an error message. The CAN
decoder continues to work with the old rule, until a valid
one has been transmitted.
6.4.3

Calculation rule data types

Since firmware version 4.3.1, the rules described in the
table below apply to the conversion of data types, taking
into account the scaling calculation:
signal_value = ( raw_value * factor ) +
offset
To make sure that the calculation remains as accurate as
possible, and that integer values will not be corrupted
even when scaling is used, the scaling calculation is
divided into two processes. The data types for "raw",
"factor" and "offset" are calculated differently.
6.4.4

Floating point scaling

Provided at least one of the values of "factor" or „offset"
have been parameterized with a floating point value, the
CAN raw signal "raw_value" will first be converted to a
floating point value (REAL64). In this case,"factor" and
"offset" are always of the floating point data type
(REAL64). The intermediate result will then be converted
into the data type that has been specified as the "Signal­
Format".The application of floating point numbers means
that rounding errors are inherent.
If the data type for "SignalFormat" is 64-bit integer, the
decimal places of the floating point value are truncated
before the final conversion from REAL64 to UINT64 or
A4461-2.0 HBM: public
CANBus