Modbus MOD10 Format to handle huge numbers
Modbus Mod10 format is an agreement on how to interpret/store large numbers.
Question: How do you handle large integer values in Modbus? Eg 100,000,000,002
Answer: Use 2 or more 16-bit registers
Both the server of the Modbus data and the Register master must agree on
If there isn’t agreement then you could face the problem that a number is served in. For example, Mod10 using 3 registers and the master thinks only 2 are being used
Slave and master agree on 2 register Mod 10
Positive / Negative numbers
Any of the registers can contain a negative number or positive number in the range -9,999 to +9,999: Note that the same formula is used whether the register is signed or unsigned
Thus, to send a negative number all of the registers being used must contain a negative number.