Call up and Set off

Call up verb - Get or try to get into communication (with someone) by telephone.

Set off and call up are semantically related in movement topic. In some cases you can use "Set off" instead a verb "Call up", when it comes to topics like convert for military use.

Set off verb - To cause to function.

Call up and set off are semantically related in movement topic. Sometimes you can use "Call up" instead a verb "Set off", if it concerns topics such as convert for military use.