Ka pāngia te tuaka Whetu (tuaka whetu/tuaka ahunga) o te mīhini whakairi mata Siemens CP20A e te hapa "wā mutunga ahunga" ina hoki ana ki te pūwāhi tohutoro, he mea noa engari me ata tirotiro. Ko tēnei tuaka te kawenga mō te akiaki i te hurihanga o te pane whakapiri kia taea ai te whiriwhiri me te whakanoho i ngā pūwero momi rerekē.
Ko te hapa 'wā mutu whakawhiti' e tohu ana i te wā e hoki ana ki te pūwāhi tohutoro, ka tukuna e te pūnaha he whakahau kia hurihia te tuaka Whetu ki tōna tūranga tīmatanga (hei kimi i tētahi tohu, i tētahi kōhao rānei), engari i roto i te wā kua tohua, kāore te kaiwhakahaere tuaka i whiwhi i te tohu 'in place' e tumanakohia ana (ko te tohu Index mai i te encoder, te tohu 'in place' rānei mai i te pūoko).






