The present invention relates to an information provider assembly to be used with a medicament delivery device for providing status information of the medicament delivery device, which medicament delivery device is provided with a medicament dose setting mechanism, the information provider assembly comprising a housing designed to be releasibly connectable to said medicament delivery device, the information provider assembly further comprising a measuring unit capable of measuring the position of a measuring surface on said medicament delivery device, which measuring surface is moved as the medicament dose setting mechanism is operated. The invention is characterized in that the measuring unit is capable of measuring the measuring surface before and after operation of the dose setting mechanism, when said housing is connected, wherein the difference in positioning of the first reference points before and after operation of the dose setting mechanism constitutes information regarding set and delivered dose of medicament.本發明有關與藥物輸送裝置一起被使用的資訊提供器組合體，用於提供該藥物輸送裝置之狀態資訊，該藥物輸送裝置係設有藥物劑量設定機構，該資訊提供器組合體包含外殼，其被設計成可釋放地連接至該藥物輸送裝置，該資訊提供器組合體另包含能夠測量該藥物輸送裝置上的測量表面之位置的測量單元，當該藥物劑量設定機構被操作時，該測量表面被運動。本發明之特徵為當該外殼被連接時，該測量單元係能夠在該劑量設定機構的操作之前及之後測量該測量表面，其中在該劑量設定機構的操作之前及之後，於該等第一參考點的定位中之差異構成關於藥物的設定及輸送劑量之資訊。
