Ideally, there are no repeated point addresses in the mapping for the same slave. If there are any, the first mapping rule found is kept.
The group parameter with value zero (0) in CMT creates a single poll for the requested point address of a certain slave unit.
The polling of multiple consecutive point addresses is recommended to be mapped under the same group (options: 1 … 255), this optimizes and speeds up the polling rate in a multi-slave setup.
When defining poll groups in CMT, it must be checked that any poll group address range does not exceed the Modbus protocol limitation of 127 registers (max address - min address) within a single poll group.