The parameters and settings of the main control functions of an HVDC system shall be agreed between the HVDC system owner and the relevant system operator, in coordination with the relevant TSO. The parameters and settings shall be implemented within such a control hierarchy that makes their modification possible if necessary. Those main control functions are at least:

1. (a)

   synthetic inertia, if applicable as referred to in Articles 14 and 41;

2. (b)

   frequency sensitive modes (FSM, LFSM-O, LFSM-U) referred to in Articles 15, 16 and 17;

3. (c)

   frequency control, if applicable, referred to in Article 16;

4. (d)

   reactive power control mode, if applicable as referred to in Article 22;

5. (e)

   power oscillation damping capability, referred to Article 30;

6. (f)

   subsynchronous torsional interaction damping capability, referred to Article 31.