Thermo Scientific NESLAB EX Series Installation, Operation And Maintanance Manual page 51

The master sets parameters in the bath by sending one of the Set Functions as shown in Table 1. The master
does not send a qualifier byte in the data field. The master should be pre-programmed to send the correct
precision and units (it could also read the parameter of interest first to decode the correct precision and units
needed).
As an RS-485 example, if the master wants to set the setpoint to 30°C, it would send :
CC 00 03 F0 02 01 2C DD
The bath responds:
CC 00 03 F0 03 11 01 2C CB
command byte
2 bytes to follow
command byte
3 bytes to follow
The checksum is the bitwise inversion of 22
(00+03+F0+02+01+2C) = 122
Take the LSB = 22
The temperature of 30.0°C is 300 decimal = 012C hex.
The qualifier byte of 11 indicates a precision of 1
decimal point and units of °C. The temperature of
30.0°C is 300 decimal = 012C hex.
The checksum is the bitwise inversion of 34
(00+03+F0+03+11+01+2C) = 134
Take the LSB = 34
B - 3