Question

Must use an internal output properly addresses

Redraw the program shown in Figure 5-57 corrected to solve the problem of some logic ignored 4.

Answer 1

Refer to Ladder Logic program shown in Fig - 5-57 in the text book rightarrow with respect to Ladder program shown in Fig 5.57 there are three Forward continuity paths (Left to Right) (A . B - Y, A - C - D - Y, E - D - Y) and one backward (right to left) (E - C - B - Y) continuity path . But the processor allows the power signal and other communication and control signals only in the Forward path . As a result the backward path (E - C - B - Y) is not utilized . rightarrow To bring the path into Forward direction arrange the contact switches E, C and B in series and connect the entire attachment parallel to first rung along with all forward paths as shown in \r\n Above figure: Ladder Logic problem to backward path Therefore By converting a backward continuity path into Forward continuity path the idle can be utilized and used for control processing by the PLC .