time delay

hi,
i am a new learner of plc. can anybody tell me how can i write a program with time delay with ladder programme

Bhupinder,

Yes, and the details depend on the PLC brand and model, and the programming software that you are using.

The first step is to determine for what the time delay will be used.

What about this: Turn a light on, wait 3 seconds, turn the light off, wait 4 seconds, then repeat the cycle?

Lancie1 said:

Bhupinder,

Yes, and the details depend on the PLC brand and model, and the programming software that you are using.

The first step is to determine for what the time delay will be used.

What about this: Turn a light on, wait 3 seconds, turn the light off, wait 4 seconds, then repeat the cycle?

Click to expand...

You got them traffic lights on your brains..




For bhupinder, depends on the PLC as Lancie says, also there are a number of different types of timers, time on, time off, pulse delay, extended pulse delay. So as Lancie says, be helpful if you stated which PLC and what type of delay you want.

Your not related to the Kumar's at No.42 are you?

You got them traffic lights on your brains..

Click to expand...

Nah, traffic lights are much too complicated for a beginner. I was thinking of simulating a Repeat-Cycle relay timer, one of the first training exercises in timers.

Assuming you don't want to use timers...I like using scan rate and doing some accumulative math. I think every PLC brand I've ever touched publishes the last scan time somewhere.

For longer periods you can also calculate from start time of event.

Nick

Hello Bhupinder,

Welcome to the forum.

Can i suggest you to google "Ladder diagram" and browse the results..that will be a good beginning....and you can use the search facility of this forum also for the same keywords.

PLC's use ladder diagrams but the format/layout is different in each PLc and is decided by the software it uses.

But in general a logic can be understood by analysing the ladders.

Check out this link.

http://www.eod.gvsu.edu/~jackh/books/plcs/labguide/egr450-38.html


Good luck.