An apparatus for interpreting a first control command and a second control command both received via a communication channel by said apparatus, the first control command indicating start of an activation period at a control element adapted to control the apparatus and the second control command indicating end of said activation period at said control element, wherein said activation period is one of a short activation period, a long activation period or an undefined activation period, said apparatus comprising: a first timer adapted to be started in response to a receipt of said first control command and to count a first predetermined time period, wherein said first predetermined time period is used to determine a short activation period; a second timer adapted to count a second predetermined time period, wherein said second predetermined time period is used to determine a long activation period, wherein the second timer is started at time-out of the first timer or simultaneously with the first timer and wherein the second predetermined time period ends after time-out of said first timer; a processing unit adapted to, in response to a receipt of said second control command during operation of said first timer, stop said first timer and initiate execution of a first predetermined action, wherein said first predetermined action corresponds to a derived control action to be executed by said apparatus for a short activation period at a said control element; initiate execution of a second predetermined action in response to a time-out of said second timer, wherein said second predetermined action corresponds to a derived control action to be executed by said apparatus for a start of a long activation period at said control element; initiate execution of a third predetermined action in response to a receipt of said second control command after time-out of said second timer, wherein said third predetermined action corresponds to a derived control action to be executed by said apparatus for an end of said long activation period at said control element; characterised in that said processing unit is adapted to, in response to a receipt of said second command after time-out of said first timer and during operation of said second timer, stop the second timer, and initiate execution of a fourth predetermined action wherein no derived control action to be executed by said apparatus is associated with said fourth predetermined action for an undefined activation period as determined by said apparatus with a duration between said short activation period and said long activation period. a first timer adapted to be started in response to a receipt of said first control command and to count a first predetermined time period, wherein said first predetermined time period is used to determine a short activation period; a second timer adapted to count a second predetermined time period, wherein said second predetermined time period is used to determine a long activation period, wherein the second timer is started at time-out of the first timer or simultaneously with the first timer and wherein the second predetermined time period ends after time-out of said first timer; a processing unit adapted to, in response to a receipt of said second control command during operation of said first timer, stop said first timer and initiate execution of a first predetermined action, wherein said first predetermined action corresponds to a derived control action to be executed by said apparatus for a short activation period at a said control element; initiate execution of a second predetermined action in response to a time-out of said second timer, wherein said second predetermined action corresponds to a derived control action to be executed by said apparatus for a start of a long activation period at said control element; initiate execution of a third predetermined action in response to a receipt of said second control command after time-out of said second timer, wherein said third predetermined action corresponds to a derived control action to be executed by said apparatus for an end of said long activation period at said control element; characterised in that said processing unit is adapted to, in response to a receipt of said second command after time-out of said first timer and during operation of said second timer, stop the second timer, and initiate execution of a fourth predetermined action wherein no derived control action to be executed by said apparatus is associated with said fourth predetermined action for an undefined activation period as determined by said apparatus with a duration between said short activation period and said long activation period.