Anti tie down

Can someone show me an example of an anti tie down program? I am using micrologix 1200.

Anti-tie downs (safety device) should not generally be implemented with a PLC (PLC is not fail safe) - however there are rare situations where this can be done safely if all of the required safety conditions are handled by other fail safe devices.

I hope I don't come off as being harsh, that is certianly not my intent, but I think this needs to be said: The implementation of an anti-tie down in ladder logic is very simple. So simple in fact that if it is not being grasped I fear that there are other critical safety issues that are not being dealt with - and that makes me very hesitant to post a solution.

Safety is not something to be triffled with.

There is an article here which will be informative. Again, if you don't get this, dont do it. You can be held personally repsonsible if someone gets hurt.

AB sells a neat safety relay module specifically for anti tie down.

MSR7R & MSR7C​

http://www.ab.com/en/epub/catalogs/3377539/5866177/4444281/4444297/4444640/​

I have used pilz for years, siemens for a little less

here a pilz link

http://www.pilz.com/english/products/safety/safety_relay/two_hand.htm