RS logix Ladder Logic question AB1500

[tjoneill]

KTM
someone correct me if i am missing something but rung 001 will NOT be true becouse T4:0.EN will go false when T4:0.DN bit goes true, not allowing the timer to start.

 

[alan_505]

As far as I am aware the T/EN bit is true as long as the rung is true.
The T/TT bit is true whilst the rung is true and the preset has not been reached.

 

[TConnolly]

As far as I am aware the T/EN bit is true as long as the rung is true.
The T/TT bit is true whilst the rung is true and the preset has not been reached.

That is correct.

Also, because it is a retentive timer, once the preset is reached, the /DN bit will be true even when the rung is false until the timer is reset.