Can anyone point me in the right direction for some sample logic to use with the 1756 ControlLogix safety controler plc. I would think that there is some type of protocall that would have to be followed, but so far I have not found anything on Rockwells site for sample programs inspite of their having guardLogix and Safety PLC as search options.

You need to download and read:
"Using ControlLogix in SIL2 Applications"
Publication 1756-RM001E-EN-P - November 2006


There is a section near the end on using the CLX in SIL1 applications, some of the redundancy is relaxed.

You probably talking about GuardLogix.
See publications:
1756-UM020
1756-RM093
1756-RM095
1791DS-UM001

Thanks Guys,

It a lot easier when you know what your looking for. Got any quick tips on how to do this, 8 megs of PDF files is just a little intimidating.

Which one? GuardLogix, or CLX for SIL2?

Try this link

http://www.ab.com/safety/

I am using 1791ds safety modules to a safety PLC> We have Sick light curtains and a bi-directional conveyor loading pallets to a machine. I have the light curtains working to the point where any intrusion stops the conveyor. Now I need to figure out how the muting sensors need to be programmed to allow a pallet to pass?? The sensors are wired to the same 1791DS-IB12 input module as the OSSD1 and OSSD2. I just don't have a clear understanding of how to make this work. Any help is appreciated

Example of how to do it:
http://www.sti.com/ltr2/access.php?file=pdf/3956.pdf

What you have to do is rely on either timing or a sequence of operations. During that sequence, you program the system to either ignore a portion of the beams or to ignore the light curtains altogether when the system recognizes that the pallet must be passing through the light curtain.

The trick is setting it up so that it must be a pallet, not an operator sticking something in front of the sensor or someone crawling through the conveyor. This means that you have to detect either a particular size and shape (multiple sensors along the conveyor belt and a certain number of them should/should not be blocked) or timing (once a beam is crossed, the curtain is muted for a particular period of time long enough for the pallet to pass through).

Here's a fully worked example for the much simpler Guard PLC but the example will work the same way with GuardLogix:
http://literature.rockwellautomation.com/i...at009_-en-p.pdf

And to CYOA don't just assume your logic will detect a pallet and only a pallet, test your logic and document the test. Having a record of the due diligence goes a long way when operators finally figure out how to sneak past the curtain and get where they don't belong.