PLC Ladder or Functional Block Program for 2 Hand Operating Relay

L1-----||-----||-----()-----L2

More tricky if they both have to be pressed within a time window (typically 0.5 sec).

yes only and only if both have to be pressed at a time with in .5sec

If you work fast enough with one hand, your other hand can still be in the press. Why a non-zero time interval?

Quite tricky to hit them absolutely simultaneously. 2-hand relays almost invariably have a window of about half a second. (Means you can't jam one button down and just operate the machine with a single button, with your other hand in the press or whatever).

Good point; harder to defeat that scheme.

Is your means this?

Your image didn't appear. Save the image to your HDD, then use the green camera tool to display it. This is what we can see on your post:

Now plz check

No - that will only produce a pulse output (which may be enough for your application), but the output will not turn off if either button is released. You would need to AND the signals from the buttons, invert the result and take it to the RESET input of BOQ3. BOQ3 should be a SET-RESET block, not a pulse device.

Pruduced using LOGO!Soft Comfort. Tested in simulation.

This is it converted to a ladder:

Dear Sir

1st of all thanks for ur guidance.

Its not working as per 2 hand operation, if we continued press any one of button for more than .5 sec and then press the 2nd button, we are getting o/p as per 1st attachment.

But we need if any one of button pressed more than .5 sec then operation should not be run.

But as per my last program or the 2nd attachment here is working as per 2 hand operation

Thanks & Regards

You have not copied my program correctly. Check the type of relay used at B001 and B002, and try again.

Have you found your error yet?

yes sir

finally i made

thanks & regards

This is what I use

A OR B--AND NOT START-------- .5 SEC TIMER

TIMER DONE-----------------------SET ERROR

NOT A AND NOT B-----------------RESET ERROR

A AND B AND NOT ERROR.--------START

Ladder and Functional Block Programming - Elsevier

Did this back in 1977 using one shot relays on a press. Still using this old tech today?

Usually done these days by a special function Safety Relay or by logic within a Safety Rated PLC.

Why do you need a 2 hand operating relay operation?

If it's for a safety application, then unless you're using a safety PLC, I'd advice against it and, go with the hardwired safety relay option.

http://www.plcs.net/contents.shtml

Dear Annon #1:

Yes, I can do this.

Thanks and Regards

( You never asked if I WOULD give you the ladder logic program, and if you have been here long, you would have realized that anonymous posters asking for something that looks like 'homework help' tend to get mainly sarcastic replies. )