Recently our local CO installed a new Lucent Technologies CO switch.I think he called it an EMS. Now with this new CO we are having
problems with our Mitel SX-200
ground start lines. Seems the SX-200 doesnt hold the ground start long
enough for the new CO to
recognize a call for dial tone. The SX-200 will pull a dial tone
about 30 percent of the time. I can start these lines manually with a momentary connection to ground. I dont
see that the ground start duration can be lengthened in the system programming options. I dont know if there is an adjustment on the trunk card itself. These are 9110-211-000 Transformer 4circuit trunk cards.
Nothing is mentioned in the manuals on ground start timing. Looking at the trunk card. there is the groundstart/loopstart switch, 4 dip switches, the busy switches and a potentiometer.
I have two identical systems at different locations . Both are behaving the same way since the new Bell CO was installed in town. Im told it is an EMS? Lucent Technologies Switch. From my end, a solution might be to add a few milliseconds to the ground start duration on the MITEL. Its acting like it's on the verge of being too short.Like I say, it only pulls a dial tone 30 percent of the time.
And I can start them manually.
I
hope the CO can make some
sort of accomodation although their Bell repair tech told me that there arent any adjustments they can make on their end. Anybody run into this kind of a problem on a newer Lucent Technologies CO?
Would appreciate hearing what you
were able to do about it.
when I ground start the line and pull a dial tone I measure 8 volts across ring and tip with a 15 ma current flow. ( current meter in series with the test set is about 20ma) (current meter in series with the Mitel PBX is 15ma)
Ground start or wink current is barely 20ma then drops to 15 ma at dial tone @ 7.9 volts across L1 L2. Is this current within spec?
Also, other measurements with system connected: (Mitel system kicks out 5.5 volts across the line) Im told this is normal.
measurement between ground and L1=47.2 volts
measurement between ground and L2=52.8 volts
I never measured these parameters on the old reliable CO.
Thanks for any help or advise.
Try reversing the polarity of the trunks and see what happens. Your problem may be due to reversed polarity on the trunks during the CO cutover. I know that this is a stretch, but it's worth a try.
Soft switches are causing problems all over the place since most major carriers are using them in an effort to save money. They cost less to operate and take up less space, but they don't provide "real" telco-quality lines. The telco employees don't know how to manage/fix them either.
Ev has a point and it is worth a try but it wouldn't explain pulling dial tone some of the time (on the same trunk - have you accessed each one individually from the console or test line). And ususally with the old SX 200 if you have the polarity reversed you get the trunks ringing in at the console.
I know there are ten dip switches on the trunk card but don't have the manual anymore for those - however I think there may be an impedance switch among those and maybe that might make a difference. - Another long shot.
Could be a problem with grounding if old COs were more tolerant of a weak ground. Measure the resistance between the approved building ground and your PBX ground... should be less than 5 ohms. And just for S&G, test the CO ground and the resistance between your PBX and the CO ground. It's just possible the Telco isn't perfect
Thanks Ed;,
As you said, after the CO cut over, the polarity was reversed, so that was the first thing I tried. It is polarity sensitive as you say and only works one way.
The lines are ringing in fine for incoming calls to their designated stations as they should. Just cant access a dial tone for outgoing
most of the time.
Yes, Harry, Thankyou, I will check for a weak grou nd and let you all know. good to know about that less than 5 ohms. Ill check that next. Thankyou.
Yes;,re: the dip switches on the trunk card, they arent really elaborated on in the manual ,just indicated, . Thankyou,I tryed altering them and it didnt seem to alter the behavior in any. I should give them another go after checking for
weak ground if the ground isnt it. Many thanks to you all.
As I recall, Re the dip switches,
10 of them are busy switches on the end of the board
with the leds., then on the board proper are two dips for each line that may be impedence related.Ill look again in the manual, see if I can make more sense out of the picture. It does say HIGH for one of the positions. I cant recall the other switch. When I go for lunch I will look again. Thanks
There are 8 switches on the edge of the card. 4 to busy out incoming, 4 to busy out outgoing. There are 10 dip switches on the card, 4 to set 3rd wire operation, 1 to ignore reversals, one to set release time and the other 4 or not used. There are Hi-Z switches on the individual trunk modules, 2 per mod. They are the 2 switch dip switches, one switch for each trunk, the HI-Z appears to be the one closest to the outer edge.
I never seen this problem, ground starts are usually reversed polarity or a bad ground. I didn't see anywhere in programming to adjust ground application time. Have you considered switching to loop?
On the mother board of the 9110-211, you have a row of 10 DIPs that control functions of the card overall. 1-4 control the 3rd wire condition for Trunks 1-4, 5 controls the "Ignore Reversals" function, 6&8 control Release Time, and 7,9,&10 aren't used on the 211 card. I don't think any of these should be a factor in drawing dial tone.
On the daughter boards you'll see two pairs of DIPS. These set the XT control and the Hi-Z; since you're in Canada these should be set to 'Closed' per the manual. I don't think either of these would interfere with dial tone, though.
Good Luck,
Thankyou for all the info on the board switches.
Ill have to keep that on file. I checked for weak
ground and no its okay. Less than 1 ohm. And both systems at two diffrent locations .5 mile apart are behaving the same. One other thought that occurred to me was the fact that the old CO was located 10 miles away and and the MITEL system pulled a dialtone from it just fine. I remember them being amazed when it was first connected. Now Im wondering if due to the long run (10+ miles) might they have added supplemental
capacity to counteract the length of the run? Now with the new switch located so close. less than 1 mile away, maybe the added capacity (if it was ever added) wasnt removed. I dont know, might this be a possibility? Ill call them tomorrow.
Thankyou for all who responded
We would use loop start lines instead of ground start except these lines are used for remote access "dial in" and the Mitel wont do a loop to loop connection. I tried that initially and thats why we ordered the ground start lines when the system was initially installed. We couldnt make the "remote access dial in" feature work with a loop start line. A old timer Mitel tech tipped us
off on that one as it wasnt mentioned in the manual either that it wouldnt do a loop to loop connection. .Took us days of trying till he gave us that tip. So thats why we ordered the ground start in the first place. Now Im wondering about an outboard converter. Ground start to loop converter if such an animal is available. then we could use loop lines.
One other question. What about the line current? Does 15ma seem acceptable to you guys? when I ground start the line and pull a dial tone I measure 8 volts across ring and tip with a 15 ma current flow. ( current meter in series with the test set is about 20ma) (current meter in series with the Mitel PBX is 15ma)
Ground start or wink current is barely 20ma then drops to 15 ma at dial tone @ 7.9 volts across L1 L2. Is this current within reason?
Mickey mouse but. You may be able to get away with using loop start and leaving the the switch set up for ground start. You'll have to turn off all alarms having to do with trunks, 'cause it will throw alarms. Card won't get the right responses from the c.o. and that will trigger disconnect alarms. Try it if you have a loop start line in the building, or can get one temporarily. The original reason for ground start was gaurunteed disconnect signal. Most loop start lines have good battery break now so GS is not really needed. Or maybe you can use GS inbound and LS outbound, if you set up 2 hunt groups. I believe at some point Mitel began allowing that. But, that may have been after the digital 1005/Lite15 was released. Anybody got a firm comment on this idea? John C. (Not Garand)
well with loop start lines you are going to have to deal with clash (possible for someone dialing 9 and grabbing a trunk that is ringing in at that moment). Not usually that big a deal, though. Still it seems strange. Just for grins (hey you've tried everything else, right?) try changing the trunk TYPE in trunk programming to 11. I know this has to do with echo and DB loss, but maybe it's causing a problem.
Lightninghorse, Some good ideas. I tried your first one connecting to a loop start line leaving the the switch set up for ground start. And it takes incoming calls fine and disconnects well as you suggested, so thats good to know that senario is a possibility, but for outgoing,using that setup, I get a busy when trying to access the line. It sees voltage when it wouldnt on a ground start line. So it thinks the line is in use. So, that doesnt work. Tried changing type to 11 as Dane suggested, but then it doesnt ring in as a direct inward dial line which give them the second dialtone. Its a type 2 right now for direct inward dial . I think I may have to take your final suggestion lightninghorse and talk them into
making their outbound calls on another loop line and leaving the ground start for inbound only if we cant get any further with the phone company in resolving this. Only other thing, I dont know if Mitel repair would modify a couple of cards for me
to make the groundstart a little longer duration.Could be as simple as adding a cap in the right place
My dad suggested I ask the phone company to check to the line for conditioning, there may be some loading coils still on it from the previous CO installation that might be causing problems.
Good possibility, but probably not a factor either way. You may have better luck getting your card(s) modified by one of the refurbers. To the best of my knowledge, Mitel no longer supports the 211 card at all. As far as that goes, the 211's are so common and obsolete, it's normally cheaper to buy one than repair one! This may be my lousy memory, but it seems to me that Mitel did come out with 1 more LS/GS after the 211. See if you can find info in the 217 manuals. John C. (Not Garand)
Okay, pondering the posts and what you all suggested and having tried the various proposed senarios. I think we have come up with a work around solution using a loop start line. Since as was suggested, a modern loop line will ring in and disconnect itself with the trunk switch in the "ground start position",, that takes care of the inbound traffic. So for the outbound traffic we connect a second trunk circuit with its trunk switch in the "loop position" and route outbound through that connection. So we would use two trunkcard circuits on the one CO loop line. So we now have inbound direct inward dial and outbound speeddial using the one loop phone line . I tested it and it is works!!
Now we can call Bell and have them cancel the ground start lines (which dont start anyway) Many many thanks for the brainstorming. God Bless you all and your families. This one really had me down for a couple of days. If there is a will there is a way if you put enough heads together.
I either missed it or did not realize it was a DID trunk. In that case try making it a 21 isntead of 2 and see if that helps.
Okay, Dane,
will give it a try.
Bry
Dane,
Tried it, and there is no difference in line siezure behavior.
It appears that what we have found so far is going to work... using
the discussed workarounds on a loop rather than a ground start line.
We wound up canceling the ground start line and going to loop start. The workaround using two trunk card circuits, one set to ground start ( to satisfy remote access requirement)for inbound calls and the other circuit set to loop start for the outbound traffic. It seems to be working okay. Ocassionally it hangs because it doesnt see what it expects on the ground start circuit. , but the Mitel times it out in 30 seconds so thats livable. BTW, Bell rep told me they were having trouble getting their payphones to work on this new Lucent Technologies EMS switch as they are all ground start. I guess they wouldnt pull a dialtone either so they wound up putting them on loopstart for the time being. The programmer for the Lucent EMS couldnt find any options that would shorten the wink time required for dialtone. I wonder if
changing "country" options might alter that parameter. These things must be sold all over the world?
Pay phones? With all the cellular out there I thought the only pay phones left were in the Smithsonian.
Yes in rural Canada, there are still payphones. Actually, we just got a cell tower a year ago where I live. Till then, we were in a dead zone.