PLM Links Table question

[Tmc]

I was having trouble adding/programming a new "Dimmer Keypad, 6-Button,2334-232" to my eisy.  From other contributors I hear this is really a 5 button device, which is why a 6-button isn't listed in the Add Device Table.  I find that really confusing, but that's not my question.  I am going to replace my 18 year old PLM 2412S with a new PLM 2413S and decided to Delete the 2334-232 and try adding it again with the new PLM.  I ran a PLM Links Table and was surprised that the Insteon address of the device still appeared in the PLM even though I Deleted it from eisy.  Is that correct, addresses don't get removed from the PLM when a device is deleted from eisy?

Thanks for your Thoughts.

[Geddy]

@Tmc first off I'm impressed that your PLM lasted 18 years. That's amazing! 

I'm confused as to your question. Is that looking at the link table in the OLD PLM or the new PLM? When did you remove the 2334-232 from IoX? I wonder if it's possible for the PLM to keep old devices for a period of time. Somebody with a lot more knowledge of when and how information is written to the PLM will need to answer this. Would certainly be a risk of having a lot of orphaned links in the PLM if a lot of devices are deleted but never actually removed from the PLM links. 

I wonder if you have the new PLM connected and made a current backup of your IoX system then restored it would that overwrite any links in the PLM? 

Interesting situation you have posed. Hopefully others have information to give light on what is expected.

(oh, and moved this out of Insteon area into IoX area since it's more relative to IoX level of discussion.) 

[Brian H]

Did you use the Administrative Consoles replace the PLM function? To replace the old one for the new one. That would replace the old PLM's six digit ID in all your modules and then put your modules known six digit ID in the new PLM. I don't think a deleted module is completely removed from the PLM but one byte of the entry is changed to indicate it was deleted. The PLM is sent a factory reset command from the software at the start of the replacement or rewriting the whole known modules addresses. That should eliminate as marked as deleted.

 

[Tmc]

The device was not removed from the old PLM.  Haven't tried switching to the new one yet.  

Thanks for moving my query, I'm not fluent on what the IoX is.  

[IndyMike]

@Tmc, you are correct that there is a record with your device address still in the PLM.  If you look at the flag column you should see a "22".  This is the sign that the ISY has marked the record as "Unused".  In order to completely remove the information, all of the links following the record would need to be removed.  Simply marking the record Unused gets the job done quickly. 

If you find that you have many "unused" records you can perform a PLM restore to rewrite the entire PLM.  The ISY will remove the unused records.

The same technique applies to devices.  The "22" is used to mark records unused, and a Device Restore will rewrite and remove the unused records.

 

[Tmc]

Thanks IndyMike.  I will look for the "22".  I have replaced quite a few broken devices over the last years, but never have I done a PLM Restore.   That might clear up a few other communications issues I'm having (hence deciding on a new PLM).

I will try that before I replace the PLM and see what happens.  But I'll have to do that tomorrow as I've run out of time today.

Thanks everyone for your help!

[Techman]

1 hour ago, Tmc said:

I was having trouble adding/programming a new "Dimmer Keypad, 6-Button,2334-232" to my eisy.  From other contributors I hear this is really a 5 button device, which is why a 6-button isn't listed in the Add Device Table.  I find that really confusing, but that's not my question.  I am going to replace my 18 year old PLM 2412S with a new PLM 2413S and decided to Delete the 2334-232 and try adding it again with the new PLM.  I ran a PLM Links Table and was surprised that the Insteon address of the device still appeared in the PLM even though I Deleted it from eisy.  Is that correct, addresses don't get removed from the PLM when a device is deleted from eisy?

Thanks for your Thoughts.

When you replace your PLM be sure to exactly follow the replace PLM procedure (see attached)

Replace PLM Procedure (EISY or POLISY).pdf

[IndyMike]

@Tmc, my apologies - I was wrong.

I just deleted a device from my system and the PLM responder links are still are still there.  I'm scratching my head at the moment...

 

Event Viewer:

Mon 02/10/2025 06:22:32 PM : [58 C9 B0 1  ] Start : Removing device from ISY

Mon 02/10/2025 06:22:32 PM : [58 C9 B0 1  ] Finish : Removing from ISY was Successful

 

PLM Table:

[IndyMike]

As usual, I could not leave this alone... Anyone who has read my posts knows that they are rarely short, and never very interesting.  Read on at your own peril...

I ran another test deleting a KPL from my PLM.  I compared the PLM link tables before and after the delete.  Observations:

1. The ISY deleted the control link (E2) for group 0 at address 14H from the table.  This makes sense - leaving the link would allow the PLM to try to interrogate the device even though it didn't exist.  Think PLM timeouts, retries, and the whole mess.
2. The ISY DID NOT delete the responder links  (A2) for groups 1 though 6 (main button and secondaries).  I suppose these are viewed as harmless links.  The can't do any damage if the device isn't there to communicate with the PLM.
3. With the "deletion" of the Link @14H, all of the following link addresses shifted up by 1.  The PLM now shows 1 fewer total links (497 vs 498).  

The above makes sense to me except for Item 3.  There is no way the ISY had time to delete the link @14H and REWRITE ALL OF THE FOLLOWING links.  Anyone who has restored a PLM knows it takes a significant period of time.  This operation took seconds.  

This leads me to the conclusion that the ISY DID mark the record @14H as "available" (22).  During the subsequent PLM link table read, the record @14H was IGNORED since it was marked as "available".  

The PLM Link read operation is very different from the device link read operation.  The device read operation is handled by the ISY through read commands for each link location.  The ISY displays all Link table information including "available" records.  The PLM Link Read operation is handled by the Insteon "Get Next ALL-Link Record".  This command apparently skips the records marked as "available". 

I now yield the soap box...

IM

 

 

[Tmc]

IndyMike,

What you're doing is interesting, but way past my understanding.  I do have a couple questions.

1. Your screenshot of your links table is quite different than mine.  Looks like a spreadsheet view where you have the filter buttons at the top.  Mine looks like:  

2. When I save  the table I get a pdf file that doesn't make any sense to me.

3. Link 325 (71.22.A6) is the device that I deleted.

4. About a week ago my PLM Links Table had 418 Links.  Today it shows 331 links.  I didn't add or remove any devices.  Why would the table change so much?

Still haven't attempted replacing the PLM or Restoring it.  May try the Restore first, maybe today.

 

 

[Tmc]

Okay, did a Restore of my 18 yr old 2412S PLM.  The address of the deleted device no longer appears in the links table, as expected.  What I didn't expect is the number of links increased from 331 to 347.  I don't need an explanation, it's just interesting.

I still intend to replace it with my new 2413S PLM.  Probably tomorrow.  I'll use the procedure provided by Techman.  Thank you for that!

[Techman]

What you're seeing is normal, the link count will vary if the PLM is active. It's best to do a link count when there's no activity.

[IndyMike]

On 2/12/2025 at 10:06 AM, Tmc said:

IndyMike,

What you're doing is interesting, but way past my understanding.  I do have a couple questions.

1. Your screenshot of your links table is quite different than mine.  Looks like a spreadsheet view where you have the filter buttons at the top.  Mine looks like:  

2. When I save  the table I get a pdf file that doesn't make any sense to me.

3. Link 325 (71.22.A6) is the device that I deleted.

4. About a week ago my PLM Links Table had 418 Links.  Today it shows 331 links.  I didn't add or remove any devices.  Why would the table change so much?

Still haven't attempted replacing the PLM or Restoring it.  May try the Restore first, maybe today.

 

 

@Tmc, sorry for the delay in responding - I was on the road.

Answers:

1. I "save" the PLM table as an XML file and then Import to Excel as an XML table.  it allows be to sort columns and select individual device addresses for inspection.  Unfortunately the values in the XML file are in decimal.  You have to convert to Hex (+dec2hex) for them to make sense.
2. Curious - my file save with an .XML extension.  Most browsers can open it and it appears as you have shown above.  In order to format the data, you can open the file with Excel or use a XML viewer.
3. The link 325 that is shown is a "responder" link.  As I indicated earlier, I believe the ISY leaves these.
4. As @Techman indicated, the PLM link read isn't perfect and can be interrupted.  I run the process 2 - 3 times in a row to make sure things are consistent.