Jog code using PLC...HELP!

[jorgemoreno]

I am new to PLCs so please bare with me on this. I am trying to implement an small application using a Micrologix 1500, basically the operation of the machine is not complicated, but it requires a jogging control using two buttons START and STOP.

1. By pressing quickly two times the STOP buttong and hold in it in the second time, then press START button it will advance one position, by "advancing one position" means that a sonic welder using a horn will weld.

2. The other option is to jog a spinning table by pressing once the STOP button and holding it, the everytime you press START button it will jog. The difference between this is that the machine will not weld.

If you can include sample code it will be really appreciated.

Thanx in advance for your time

 

[Macbeth]

Useing the stop control for any thing other than STOP is not advisable. Look at you PLC see see if aditional inputs are avalible Buy a switch label it jog then move on to the next project. The stop is STOP, Stop should allways override Start.

How ever some time creative programing is required.
Try this:
Every time the stop button is pushed reset a timer (2sec) And
Add one to a counter.

If the timer times out Reset the Counter.
Timer only time it stop is released

If the counter => 2 and {jog mode)
STOP button is pressed while the start is pushed then JOG

 

[jlada]

MacBeth is right. It is false economy to hang multiple functions off of single actuator inputs. Not only will this confuse the operators, but much worse, you'll find yourself in front of a board of inquiry because somebody found a combination of your 'clever' inputs that you didn't think about. This could end up doing a body grievous harm. Don't let somebody (probably the business owner) pressure you into doing something you'll regret in order to save a few dollars. If you're out of inputs - get more.

Safety first...

 

[SteveMeisel]

Start and stop buttons should not play double duty.
This has great potential for some one to get hurt and or cause machinery damage. I would think again about this one.