I'm brand new to ladder logic and this is a simple question but for some ungodly reason I cannot get my head around this.
In a relay circuit, the circuit is drawn in the de-engerized state. When power is turned on the relays change state until the power is removed. Simple.
But this is where I'm confused in ladder logic. When a signal is put to an address is it a momentary signal or a constant signal?
With the image below, I will try to explain my issue.
Now if I give a signal to 000.00 it is going to close that contact and start the timer. But it is also going to open the NC contact since it is on the same address, correct? Now if the signal is a constant signal, the NC contact will stay open and this ladder will not work.
But if it is a momentary signal, then yes I understand how this would work to a point.
Once a signal is sent to the NO contact, the contact closes triggering the timer. Once the timer gets to the set time it sets a flag and moves to the next rung on the ladder. Since the tim001 is a NC it continues to the counter where after a count of 2k it closes the CNT002 contact. ok.
Why is there a NC contact address 000.00 hooked to the counter? If it is a return path to the top of the ladder the circuit would stop after a count of 1 since the other contact is open "as the signal is momentary", correct? Can anyone with a little understanding that I'm new to ladder logic try and assist please?
In a relay circuit, the circuit is drawn in the de-engerized state. When power is turned on the relays change state until the power is removed. Simple.
But this is where I'm confused in ladder logic. When a signal is put to an address is it a momentary signal or a constant signal?
With the image below, I will try to explain my issue.
Now if I give a signal to 000.00 it is going to close that contact and start the timer. But it is also going to open the NC contact since it is on the same address, correct? Now if the signal is a constant signal, the NC contact will stay open and this ladder will not work.
But if it is a momentary signal, then yes I understand how this would work to a point.
Once a signal is sent to the NO contact, the contact closes triggering the timer. Once the timer gets to the set time it sets a flag and moves to the next rung on the ladder. Since the tim001 is a NC it continues to the counter where after a count of 2k it closes the CNT002 contact. ok.
Why is there a NC contact address 000.00 hooked to the counter? If it is a return path to the top of the ladder the circuit would stop after a count of 1 since the other contact is open "as the signal is momentary", correct? Can anyone with a little understanding that I'm new to ladder logic try and assist please?