Spectrasensors OXY5500, Operator'S Manual, Page: 88 / 140

Oxygen Analyzer
4
–
2 4900002239 rev. G 7-11-17
Function Codes
Available public functions are:
•
3 : Read Holding Registers
• 4 : Read Input Registers
•
16 : Write Multiple Registers
Please note that function codes 3 and 4 are fully interchangeable as they
behave in the same way.
Data Formats
Float
The Float refers to the floating point according to IEEE 754 (Single Precision).
This format requires two registers obtaining 32 bit where each register contains
the high byte in its first bit.
For example, if the float value is 20.56 (int32), represented as 0x41A47AE1
(hexaint32), it is written in two consecutive registers, where the first register
is 3499. Therefore, the value has to be transmitted in the following way:
Int32
All int32 values are 32bit-wide integer values. The example given in the
previous section applies here as well.
Character
The definition is as follows:
•
8bit ASCII-Code table according to ISO-8859-1 (Latin-1 Western
European)
Function code 16 may be used with broadcast (device ID = 0).
Codes 3 and 4 may not be used with broadcast.
Register 3499, high byte 0x7A
Register 3499, low byte 0xE1
Register 3500, high byte 0x41
Register 3500, low byte 0xA4