RsLogix 5000 Module Properties/ Electronic Keying ?

RslLogix 5000 In I/O configuration/ Module Properties and Electronic Keying what do the options of “Compatible Mode, Disable Keying, Exact Match” represent I’m trying to understand what each of these functions do, if configuring a 1756-IB16D module
Thank You

Adam303 said:

RslLogix 5000 In I/O configuration/ Module Properties and Electronic Keying what do the options of “Compatible Mode, Disable Keying, Exact Match” represent I’m trying to understand what each of these functions do, if configuring a 1756-IB16D module
Thank You

Click to expand...

Ken Roach is probably the best one to answer this, but this is my understanding.

Exact Match is the best and should match the Major and Minor Revisions.
Compatible Keying is next best if you have a slightly different Revision Installed.
Disable Keying is the least desirable, but may be necessary if you have a 3rd Party Card, or a Revision that is not supported.

I am sure this is covered in one of the Hardware Manuals, but I am not sure which one, I don't remember seeing it in particular.

How did I do Ken?

Stu....

So basically the electronic keying is used for major and minor revisions of the module that I'm using, now I'm guessing I have some understanding of the Electronic keying and its function.
Thanks I sure Ken will add on

Adam303 said:

So basically the electronic keying is used for major and minor revisions of the module that I'm using, now I'm guessing I have some understanding of the Electronic keying and its function.
Thanks I sure Ken will add on

Click to expand...

I did some searching around, and found the information on Keying in Appendix B of this Manual.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1756-um001_-en-p.pdf

Stu....

Adam303 said:

Thank You I appreciate the help

Click to expand...

No problem, I hope that Appendix B will answer all your questions. If not, come back with specific questions, and I am sure someone will be able to answer it.

Stu.....

I would say that Compatible Keying (the default) is what you almost always want.

Compatible keying specifies a minimum acceptable revision. If you add the 1756-IB16D and specify major revision 2 for example then the standard keying would be for revision 2.1. Any revision at least 2.1 would be "compatible". If you specified revision 2.7 then any spares you have must be at least revision 2.7 as anything older would be incompatible. As long as the revision is compatible a replacement unit can simply be plugged into the chassis and the controller will load the configuration to the module. No program changes would be required.

Exact match is all too often chosen without understanding the future consequences. If you specify an exact revision then the system will compare the program's expected revision to the module's actual revision. If they do not exactly match then the connection to that module will fail. How likely is it that a new module purchased several years from now to replace a failed module will have the exact same revision as the older original module? This means someone would have to change the program to match the replacement module anytime a module is swapped.

Now, there are reasons for Exact Match. Some applications may require some sort of agency certification were only documented equipment is allowed and this might go all the way down to the revision level.

Disable keying would typically be a temporary setting telling the system to use whatever module is present regardless of the revision or catalog number. This can be handy for example if the part that failed were a 16-pt module, but the only spare available was a 32-pt. You could disable keying temporarily until the correct module could be obtained.

Hope that helps,

OG