Ladder Logic

[beginner2011]

Hi

I was wondering if anyone would be able to help me with a problem i have.

I have designed a window cleaning gondola control program which controls the vertical movement of the gondola down the face of the building. The general description of this program allows the gondola to be lowered at 2 different speeds. On approaching the ground, a 'ground proximity' detector will alter the speed of decent and on finally reaching the ground the operation of lowering will be stopped.
If however the operator senses that the wind speed exceeds a tolerable level he/she can push a 'panic' button and the gondola will be automatically lowered to the ground at 'creep' speed.

Ive specified the operation of the program using a ladder diagram (attached).
I would like to add an additional feature to the system that will toggle an LED every 0.5sec to show it is operational.

Could anyone tell me how I would add this to my ladder diagram.


Thanks
Robert

 

[Grossel]

Hi.

If I where in a gondol high above ground I would rather want to get down quickly BEFORE the wind picks up. And also have a look at the weather forecast.
How about adding a grid of wind sensors in surounding area that can meassure if there is a great chance that a wind cast is imminent?

Having a second function that operate nearly independent on the main function, you should let it have its own address space. Just draw up the blink function as if it was the only function, but use some of the existing functions to activate or deactivate it (just by adding a couple of extra switches).

 

[mbarazeen]

Ive specified the operation of the program using a ladder diagram (attached).
I would like to add an additional feature to the system that will toggle an LED every 0.5sec to show it is operational.

Could anyone tell me how I would add this to my ladder diagram.

Robert

you can provide anoher contact for operation status to enable (trigger) a miltivibrator that drives the LED.