The database in any Prosoft module is structured in 16 bit integer words. When doing any bit level Modbus function code the database must be referenced at the bit level. For example: Word 0.0 = Modbus coil address 0001, Word 1.0 = Modbus coil address 0017. Word 100.0 = Modbus coil address 1601. To get the Internal bit number just take the register number times 16 to get the starting word.bit address.
******Note: The only exception to the above rule is in the 3100-MCM and 3150-MCM configured as a master and using a function code 2. in this scenario the ?source address? is at the word level not the bit level.******