Matsatsing ana, PLC e ka amohela li-encoder le li-sensor signals ntle le amplifier, joale monate oa "mohloli" le "drain" ke ofe? Ke feela tlhahiso ea PLC e tla ba le mehopolo ea "mohloli" le "leakage".

Ha e le hantle, ntle le PLC ea Japane, ha ho hlokahale hore li-PLC tse ling li sebelise khutsufatso e kang "mohloli" le "drain", empa PNP le NPN li ka sebelisoa ka ho toba.

PNP ke mohala oa sechaba o nang le matla a tlase, 'me NPN ke mohala oa sechaba o nang le matla a phahameng. Ha feela kamano ena e nepahetse, ho bonahala eka ha ho na taba hore na maikutlo a "mohloli" le "drain" a khutlisetsoa morao. Leha ho le joalo, khopolo e 'ngoe "positive logic le negative logic" le eona e fosahetse, e leng se tla etsa hore letšoao le khelosoe.

Positive logic le negative logic

Lipotolohong tsa mofuta oa PNP, terminal e tloaelehileng ea phepelo ea motlakase le lets'oao e maemong a tlase a 0V. Ha tlhahiso e le boemong bo tlase, ha ho na phapang ea motlakase le terminal e tloaelehileng, ka hona ha ho na tlhahiso ea lets'oao le matlafatsoang (boima ba dijithale ke 0). Ke feela ha ho kenya letsoho ho le boemong bo phahameng, ho na le phapang ea motlakase le "terminal" e tloaelehileng 'me lets'oao la ho fetoha le matlafalitsoeng le hlahisoa ka boemo bo phahameng. Mokhoa ona oa digital (palo ea digital ke 1) e sebetsang hantle ha pontšo e le boemong bo phahameng e bitsoa PNP positive logic.

Potolohong ea NPN, terminal e tloaelehileng ea phepelo ea motlakase le lets'oao le maemong a holimo (tšobotsi ea potoloho ena ea amplifier). Ha tlhahiso e le boemong bo phahameng, ha ho na phapang ea motlakase pakeng tsa ho kenya letsoho le tlhahiso, kahoo ha ho na tlhahiso ea pontšo ea ho fetola (palo ea digital ke 0). Ke feela ha ho kenya letsoho ho le boemong bo tlaase (ho etsa funnel), ho na le tlhahiso ea pontšo ea ho fetola, 'me pontšo ena e sebetsa hantle (tekanyo ea digital ke 1) mokhoa oa digital ka tekanyo e tlaase, e bitsoang NPN negative logic.