RSLogix 5000 Timer question 1

[lhunerjager]

This might be a silly question and I might be doing it right, but I'm having a hard time verifying.

I'm just adding a simple routine to control vibration on a hopper.

Conditions: The conveyor must be running / once started by the operator it will run a one hour cycle and then stop / it must be restarted by the operator to initiate a new cycle.

Problem: I'm having trouble verifying whether or not I need a reset instruction on this logic (I'm attaching it - simple)



Any help or affirmation would be appreciated. I'm pretty new at all this.



THANKS!!!!!

 

[xnuke]

I'm a little rusty on my programming, but I'm pretty sure the VIBRATOR_8A_TIMER.EN bit in Rung 0 won't allow the timer to reset when it finishes timing. I think you should use the VIBRATOR_8A_TIMER.TT bit instead. This will seal in the start pushbutton bit, but only while the timer is timing. Once the timer finishes timing, it'll reset.

For a TON, the .EN bit is true whenever the rung logic ahead of the timer is true.
The .TT bit is true when the PRE<ACC and .EN is true, and then when PRE>=ACC or .EN is false, .TT goes false.
The .DN bit is false when the PRE<ACC or .EN is false, and then when PRE>=ACC and .EN is true, .DN goes true.

In Rung 1, you don't have the timer controlling the motor. You should replace the START_VIBRATOR_8A bit with VIBRATOR_8A_TIMER.TT, get rid of the seal-in contact VIBRATOR_8A since it isn't needed as the timing bit remains true while timing, and also delete the VIBRATOR_8A_TIMER.EN instruction from the rung. If the stop pushbutton is a normally-closed pushbutton as it should be for safety, you should change the instruction type in the logic from NC to NO and move it to Rung 0 downstream of the parallel branch connection so that it turns off the motor and resets the timer simultaneously.

Since I don't know what the CONVEYOR_8A_RUNNING tag is, I didn't comment on it. The jog instruction looks okay.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[lhunerjager]

Thanks xnuke!!!!
CONVEYOR_8A_RUNNING is the run status of the conveyor and I don't want the vibr-ator running without the belt running.

Much simpler way to do this.
I'm attaching the new logic and from what I can see, you're 100% correct.

Thanks again.

 

[xnuke]

Your welcome. Be sure to test the code before you start running it on your system to make sure it works as intended.

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.