YSI IQ SensorNet MIQ/A-MOD Module - Manual (Page 33)

MIQ/(A-)MOD Data transmission
33 ba76021e01 01/2012
For Modbus applications that can independently interpret floating point
numbers (or allow to select a data format for certain registers), the byte
order the data interpretation is based on should be checked.
INT16 In the INT16 format, the data for the sensor model and status info is
transmitted. The data consists of two bytes. The assignment is carried
out in Motorola format ("big-endian", the higher value byte first).
INT8 All other data are transmitted in the INT8 format. This data consists of
one byte.
The data for the measured value status of the main and secondary
measured values are encoded jointly into a single byte. Bits 7-4 encode
the status of the main measured value, bits 3-0 encode the status of the
secondary measured value.
Bit representation Information
High byte
Low byte
MSB LSB