Data Mapping from PLC Program to Safety PLC Program

[hugheydarryl 0]

I am installing an area scanner on a machine and have used the manufacturer EDS file to create data structure for the scanner.  The data file is created automatically as a controller scoped data file.  I have a safety PLC program and cannot access the data from the regular PLC program.  Is there a way to map the data from the PLC program to the safety program?

[pturmel 160]

You cannot.  The safety program can only use input that comes from safety-rated sources.  Such a scanner should support CIP Safety, in which case the data will be marked reliable for the safety program.

[BobLfoot 302]

8 hours ago, hugheydarryl said:

I have a safety PLC program and cannot access the data from the regular PLC program.  Is there a way to map the data from the PLC program to the safety program?

Take a look into this manual - https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm093_-en-p.pdf - I believe the section on Standard Tags in Safety Routines (tag mapping) -- may accomplish what you're looking for.   

BUT HEED THE WARNING, YOU ARE RESPONSIBLE FOR THE INTEGRITY OF IMPORTED!!

[pturmel 160]

1 hour ago, BobLfoot said:

 Standard Tags in Safety Routines (tag mapping)

Oooo! I never noticed that feature.  Looks like a good way to get yourself in trouble (of both moral and legal varieties).  Particularly if trying to use an area scanner to protect humans without using reliable methods.

[hugheydarryl 0]

We have been doing this for about 10 years using an Omron area scanner on some of our machines.  These were new machines and were set up by an outside integrator.  We used physically wired outputs for zone switching and only use the checksum over ethernet to make sure the scan area had not been changed.  These scanners setup a tag in the PLC and it also set up a module defined tag that I can select to use in the safety PLC.  I would create a tag and select the type which allowed it to be read in the safety PLC portion.

These scanners are wearing out and very difficult to get now and Keyence is able to supply us with new scanners that we can use in the same fashion with the wired zone selects and the same OSSD outputs.  When I set up the scanner it created the data structure for the PLC and it also created the module defined tag structure for the safety program .... however the safety PLC tags are not updating like the standard PLC tags.  I just figured ... I was missing some important step or possibly a setting in the scanner software itself.  

I didn't set up the original scanners and just trying to keep the machine plugging along.  I am just trying to keep the same structure as what is there.

The other option was to convert it all over to CIP safety scanners ... however I have not ever set that up at all.

Thanks for info.

 

 

[hugheydarryl 0]

21 hours ago, BobLfoot said:

Take a look into this manual - https://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1756-rm093_-en-p.pdf - I believe the section on Standard Tags in Safety Routines (tag mapping) -- may accomplish what you're looking for.   

BUT HEED THE WARNING, YOU ARE RESPONSIBLE FOR THE INTEGRITY OF IMPORTED!!

I found that our machines were done completely with this mapping procedure.  I was able to accomplish exactly what I needed.  Thank you kindly! 

[BobLfoot 302]

On 5/14/2023 at 9:28 PM, hugheydarryl said:

We have been doing this for about 10 years using an Omron area scanner on some of our machines.

 

 

Any time I hear "That's the way we've always done it and it works" in the context of a Safety Discussion I get worried.  

In the 1960's it was recommended by the American Academy of Pediatrics that a solo parent and solo child in a car, both ride in the front seat, so the parents arm can restrain the child.

We all know better today and what worked 10 years ago, should be reviewed today to see if there is something better.

[hugheydarryl 0]

Yet we lived thru the 60's and we are here to have a discussion.  Have you ever seen the OSHA approved cowboy?  The PLC is safety locked with safety signatures.  Not trying to make something unsafe ... but safety is #1 until it interferes with production.  Mention how much upgrades will cost and watch them turn a blind eye.