EET-215 Lecture 3: TIMERS - PLC
Document Summary
Timers: to provide time delay, to keep something for a specific time then turn off. There are three types of timer instructions available in a: timer on-delay (ton, timer off-delay (tof, retentive timer (rto) They are conditioned by the input instruction preceding it. If preceding input condition is true, the timer instruction is energized. (=set, = become true, = turns on, = goes high) In timer there are 3 bits: done bit(dn, enable, timer timing. In word 0 of the plc timer instruction, bit 13 is called the done bit, abbreviated as /dn. In word 0, bit 14 is called thentimer timing bit. (tt)
