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Dropping super loop

Dropping super loop

Dropping super loop

I have a meridian 81c with three super loop cards (two ports each) connected to 6 shelves.  It seems I loose connectivity between the controller and super loop each night that it rains and the switch goes through its midnight routines.  

The only way I can re-establish a connection is to disable the loop, remove the card, re-insert the card, and then enable the loop.  Simply disabling the loop and the controller and re-enabling does not work.  The connection to the controller card then re-establishes and I can bring the shelf up.  Seems to be on the same shelf.

Any troubleshooting ideas?  Thanks so much.

RE: Dropping super loop

If you have a spare NT8D04 (superloop card) I would swap out the one that supplies that shelf. If not swap it with one of the other superloop cards that is not having a problem. If the problem follows then get a replacement. If not then try swapping the XPEC (controller) with one of the other ones that is not having issues. If trouble follows then replace the card. If the trouble stays on same loop with different hardware, look for any errors that occur right before this happens and post them. Let me know

RE: Dropping super loop

I have swapped the nt8d04 with a new one and the problem persists.  I will change the xpec controller this evening and see what happens.  

I am an old pro at adds, moves, changes and such, but know very little about how to go back and look at error messages from the past - it takes me almost 30 minutes to get in when this happens and all the messages are long gone off the console.  Any quick thoughts or references to manuals would be helpful.  

RE: Dropping super loop

If you are not succesfull in pin pointing the issue by swapping the cards. I would try one last effort (before moving onto the next possible HW failure). On your XPEC you have upto 4 slots on the backplane of the IPE you can plug the loop cable into. As long as it is a CONT 4 and the IPE shelf is 1 loop. An easy way to tell (if it is 1 loop)is to look on the backplane (from the rear of the IPE, through the panel with the 4 quick lock screws) look in the center where the loop cable/s plug into the IPE. If there are more than 1 than you have more than 1 loop on that IPE. More than likely (from your description) you are not setup with more than 1 loop on your IPE. It more than likely is plugged into the first slot (either 0/1 can't remember what it starts with). Once the XPEC and loop are disabled you can move it to one of the four ports on the back of the CONT 4 card. The reenable the loop and XPEC and test. This is not likely but is worth a try. If the problem persists on this IPE wafter you swap the XPEC. Good Luck

FYI: Also look at Loop cable itself. If these tests fail.

RE: Dropping super loop

Could not bring the shelf down yesterday to change the nt8d01, but as luck would have it, it did not rain and everything worked fine.  

My IPE is made up of one loop and I have had to move to another port on the NT8D01 when a port went bad before.  I have since moved to another port on the controller, but the problem persisted.

It seems very odd that this only happens on rainy nights - I thought during thunderstorms, but there had been no lightening in the immediate vicinity the last two times, only heavy rain.

We have the switch on an isolated ground (just rechecked by an electrical contractor) and a new surge arrestor put on the main power feed.

Any chance this problem could be coming in over my PRI's???? Or would it be more likely to be a feedback from a modem or fax internally???  This is all I can think of.

RE: Dropping super loop

I remember clearing a problem once changing the "slot" that the IPE cable is plugged in to. They are marked SL0, SL1, SL2 and SL3. Not a bad idea BMiles....

Make sure you check both all the ends of that cable(s) (there is an intercabinet cable on the CE side) to make sure they are fully connected. You might want to look inside where the cable connectors touch each other for any corrosion that may be there due to humidity.

Another thing that comes to mind. How humid is that room? Do you have Air Conditioning that will maintain a reasonable humidity level? It is important, if you have a environment issue the problems could manaf in other areas.

RE: Dropping super loop

If the card comes only after reinserting it then you also can try changing the loop(Backplane slot),

Remove the cable from the this SNET card and put on to some other SNET card configured in another loop.-If this works your slot or SNET has some problem -If this fails you can doubt on cont-4 and cable


RE: Dropping super loop

The Humidity in the room is 53% with a temp of 70.  Does this sound reasonable?

Had another outage on Thursday night (no rain, no lightening) during the midnight routine.  Loop 4 must have dropped because both shelves went down.  When I came in about 30 minutes later the shelves were back up but one DTR card was still down on the shelf that has not been giving problems as of late.  I have changed the CE cable to slot 3 and still the same results. This is a new NT8d04B card supposedly so I hate to change it again.   

If I can I will change the cables to other loops.  
Since I have three loops, can I change the cables to the shelves around without any programming changes?  

Is there a way to look back at the errors that may have been produced during a midnight routine?

This is driving me crazy.

RE: Dropping super loop

Do you run your PHSTs (Previous History reports) every morning?  Go to Ld 22, PRT, PHST.  PHST will print all messages since the last time the PHST was run.  AHST (All History reports) will print the entire contents of the memory.  I would suggest doing this from either a command console that is set to print or capture the data or dial in and capture the info through Hyperterminal, ProComm, etc.

As a side note, you might want to set up a workstation that is Direct Connected to your console and run a capture program (HyperTerm, ProComm, whatever)so that all message generated on the console are captured to in a text file.

RE: Dropping super loop

Sounds like a problem I'm having here. Do you have any FIJI cards on your switch? If so that may be the problem. We are having some hardware issues like you are describing on an 81C and we have found out that our FIJI cards need to be replaced. I have superloops dropping during midnight routines, static on Miran 3 cards, and issues with controller cards. I'm getting replacement FIJI's from our Nortel vendor and that should hopefully solve the issue.

RE: Dropping super loop

If you are having trouble on both shelf 0 and 1 then I would not suspect the NT8D01 as being the trouble as you are dealing with two different ones.  You could try moving  the NT8D04 card from the left slot to the right slot in the Network shelf.  You have to reprogram the card from left to right or vice versa depending on where it is orginally.  In other words SuperLoop 4 is in the normal slot for loop 4 then that is the left slot.  Slot 2 is the normal slot for Superloop 4.  Move the card to slot 3 and reprogram in LD 97 to the right slot.  It will promt you for the slot (left or right - default is left) in LD 97 When you change it then move the NT8D04 to the one you programed

RE: Dropping super loop

Bloodztone -

I have three FIGI cards, but have not seen any errors that I could connect with them.  How did you find yours were bad?

Unkalary -

Would I have to out all my TN's when I move the network card.  I may have to wait to try later - sounds like a lot of involvement - not to say I may not have to in the end.  My superloop takes up physical slot 2 in each net shelf and there is an msdl card in physical slot 3.  Not sure how to make this happen.

Nothing has happened since the July 3rd, but I do have a machine capturing all the messages.  Hopefully I will have some data to share soon that may show what is happening to these loops.  All suggestions are welcome.

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