# cbToEngUnits()

Converts an integer count value to an equivalent single precision voltage (or current) value. This function is typically used to obtain a voltage value from data received from an A/D with functions such as cbAIn().

## Function Prototype

C/C++

int cbToEngUnits(int BoardNum, int Range, unsigned short DataVal, float *EngUnits)

Visual Basic

Function cbToEngUnits(ByVal BoardNum&, ByVal Range&, ByVal DataVal%, EngUnits!) As Long

## Arguments

BoardNum

The number associated with the board when it was installed with InstaCal or created with cbCreateDaqDevice().This function uses the board number to determine the resolution and polarity values to use for the conversion. BoardNum may be 0 to 99.

Range

Voltage (or current) range to use for the conversion to engineering units. When using this function to obtain engineering units from a value received from an A/D board, keep in mind that some A/D boards have programmable voltage ranges, and others set the voltage range via switches on the board. In either case, the desired range must be passed to this function.

Refer to board-specific information in the Universal Library User's Guide for a list of the supported A/D ranges of each board.

DataVal

An integer count value (typically, one returned from an A/D board).

EngUnits

The single precision voltage (or current) value that is equivalent to DataVal is returned to this variable. The value will be within the range specified by the Range argument using the resolution of the A/D on the board referenced by BoardNum (if any).

## Returns

- Error code or 0 if no errors.
- EngUnits – the engineering units value equivalent to DataVal is returned to this variable.

## Notes

- This function is not supported for hardware with resolution greater than 16 bits.
- The default resolution of this function is 12 bits, so if the device referenced by BoardNum has neither analog input nor analog output, the result will be a 12 bit conversion.
- If the device referenced by BoardNum has both analog input and analog output, the resolution and transfer function of the A/D converter on the device is used.