A subject of growing interest in mathematics education is the affective domain and its effects on the teaching and learning processes, giving rise to different models of its components and conditioning factors. In this paper, we apply the ontological and semiotic categories from the Onto-Semiotic Approach (OSA) to research in mathematics education, to build an inclusive and systematic model to consider affective situations, practices, objects and processes, as well as the corresponding dualities: personal -- institutional, ostensive -- non-ostensive, extensive -- intensive, unitary -- systemic, expression -- content. The dynamic character of affects (emotions, attitudes, beliefs and values) and their relations with the epistemic, cognitive, interactional and resources is modelled by the didactical configuration and didactical trajectory notions, theoretical tools which include the affective sub-configuration and sub-trajectory as key components. Another result obtained from this work is the revision of the indicators of affective suitability proposed in previous works.