This format is also used for the representation of channel data from input modules in the VBOX serial data stream.
A 32 bit number YYYY can be split it into four bytes, the first byte is a signed exponent and the next three are a signed mantissa.
e.g. if YYYY = 0x03 0x12 0x11 0x00 this equates to exponent = 0x03
mantissa = 0x121100 or 1184000 decimal
Therefore the value is 1.184000E03