Trolex XD One, User Manual

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AIR XD USER MANUAL 58
48 PM A “Average 1” (upper 16 bits)
50 PM B “Average 1” (upper 16 bits) Float32_t µg/m^3
49 PM B “Average 1” (lower 16 bits) Float32_t µg/m^3
51 PM C “Average 1” (upper 16 bits) Float32_t µg/m^3
53 PM D “Average 1” (lower 16 bits) Float32_t µg/m^3
52 PM C “Average 1” (lower 16 bits) Float32_t µg/m^3
54 PM D “Average 1” (upper 16 bits) Float32_t µg/m^3
56 TSP “Average 1” (upper 16 bits) Float32_t µg/m^3
55 TSP “Average 1” (lower 16 bits) Float32_t µg/m^3
57 PM A “Average 2” (lower 16 bits) Float32_t µg/m^3
59 PM B “Average 2” (lower 16 bits) Float32_t µg/m^3
58 PM A “Average 2” (lower 16 bits) Float32_t µg/m^3
60 PM B “Average 2” (upper 16 bits) Float32_t µg/m^3
62 PM C “Average 2” (upper 16 bits) Float32_t µg/m^3
61 PM C “Average 2” (lower 16 bits) Float32_t µg/m^3
63 PM D “Average 2” (lower 16 bits) Float32_t µg/m^3
65 TSP “Average 2” (lower 16 bits) Float32_t µg/m^3
64 PM D “Average 2” (upper 16 bits) Float32_t µg/m^3
66 TSP “Average 2” (upper 16 bits) Float32_t µg/m^3
68 Laser current / mA Uint16_t mv/bit
67 Air XD supply voltage Uint16_t mv/bit
69 Fan current / mA Uint16_t mv/bit
70 Status register Uint16_t
MODBUS itself does not define a floating point data type but it is industry standard to use the
IEEE-754 standard for defining floating point numbers. There is, however, there is no clear-cut
definition of the byte order of the data payload.
By default, the Trolex Air XD XD uses a little-endian format for the floating point numbers
split across two 16-bit MODBUS registers. If this is not compatible with your system and a big
endian format or byte swapping is required, the byte ordering can be switched using the
on-device menus as shown below.
12.4 Reading floating point registers
Air XD_User manual_P5628.1600_Rev D