Sensoray 118 - Manual (Page 15)

Sensoray Model 118 Smart A/D™ Instruction Manual 13 Programming
// Send a floating point value to the Smart A/D board.
VOID SendReal( USHORT BasePort, DOUBLE Value )
{
int exponent;
DOUBLE mantissa = frexp( fabs( Value ), &exponent );
if ( exponent < -127 )
{
SendWord(0);
SendWord(0);
}
else
{
SendByte( (UCHAR)( mantissa * 16777216.0 ) );
SendByte( (UCHAR)( mantissa * 65536.0 ) );
SendByte( (UCHAR)( mantissa * 256.0 - ( Value > 0 ? 128.0 : 0.0 ) ) );
SendByte( (UCHAR)( !Value ? 0 : exponent + 128 );
}
}