As default Maximum Demand Current is being taken from CT Primary Current definition.

Use PAS to customize this definition in SATEC device.

Choose menu item Meter Setup->General setup>Device Option.

Input required value into field Maximum Demand Load Current instead of default "CT" and then press Send button.

Default Ampere Demand period is 900s=15 minutes.

That is Block Ampere Demand. It is meaning average current per this period. 

Maximal Ampere demand is being taken as maximum value of all block ampere demands per required period (For example: Year).

It required period is one year - one time per year Maximal Ampere demand should be reset.

Yearly (in this case) Maximal Ampere demand should be read from the device before the reseting.

The value can be read online directly from appropriate Modbus register.