sundance-communications.com/forum Forums TDM Business Telephone Systems Toshiba Telephones & Systems CIX 670 Line Cut Off Problem

Help!

6 lines on a CIX 670, when dialling out to any number, the line will disconnect the moment the called party answers the call. Phone returns to idle state.

Eg.
- Idle DKT
- Press LINE 1 (hears dial tone)
- Dials number ... ... ...
- Hears ring back tone
- Called party picks up
- "click" = line cuts off
- DKT returns to idle state

Randomly, the call will also disconnect in the midst of dialling.

Using "9" (LCR), the chances of having a proper call setup (conversation) is HIGHER!

CIX 670 with BCTU2F, 2xBWDKU, 1xRCOU/S and backup battery.

Tried on few different phones, same outcome. All 6 lines, same outcome.

Its probably a telco problem, but didn't have a butt set/meter to test the incoming lines. Going back tomorrow armed with a buttset and meter

Any insight appreciated.

You are on the right track....See if you can recreate the problem at the demark. Make sure Telco is maintaining proper voltage.

Keep us informed....................

Dan

Sounds like you answered your own question. Go back with tools to test the lines and line voltage. Dont know if you use lightning protection on the lines but that maybe a issue also.

As Voyager indicates, put a buttset on the line after disconnecting it from the CIX. With this isolation, you have 100% crystal clear knowledge that the Toshiba is possibly at fault or not.

It indicates that the circuit is dropped when answer supervision is activated. I don't see anything in the CIX that would drop a call upon answer supervision (current reversal) occurring. Most anything is theoretically possible, but probably 999 to 1 it is telco and your job to prove it is them not you.

I've seen this a few times before at different customers. Recycling the power usually fixes it.

Hi guys, thanks for the replies.

Findings:
Disconnecting the CIX, using a direct line. It works fine! No problem in establishing/disconnecting a call.

Using a meter:
Idle voltage is +38V
Seized line is -5V
When call is answered, +5V
and then immediately jumps back to +38

My homework tells me:
- at least 48V (+/-5V) is required for proper operation.
- answer supervision (voltage jumping from -ve to +ve) is supported by CTX/CIX
- there are 2 other lines at this customer site thats from a different exchange. Once these 2 lines are siezed, they stay at -5V throughout the whole call. These lines don't cut off all the time (maybe 50%)
- As expected, Telco denies all responsibility.

More updates tomorrow

Thanks Again.

1. Did you try Phonemasters suggestion and power down/power up to see if that works? He is great at troubleshooting and that would be an easy test.

2. Very smart using a meter and thanks for the results.

3. If you power down/power up as Phonemeister suggested, you will know if your voltage is +38 or +48 and will know if it is fixed or is telco problem. [sigh]

4. Please refer to 1. above.

5. Please refer to 1. above.

6. Please refer to 1. above.

Hello again (bunny, phonemeister, SSPhone, Voyager, and others)

Sorry, I forgot to mention that I've recycled the power (many times). I've even brought a new CIX100 system to customer site for testing, with the same results.

Any of you guys familiar with exchanges? Apparently this exchange is an AXE 10 (Ericsson) switch. Telco insists that the +38V is NORMAL. Is it?

Anyone know anywhere I can get more info on exchanges? Trust me, I've googled. The net is a wide wide web... or maybe I dunno what to look for...

I'm really losing sleep on this dumb problem. *panda-eyed*

Ask them to roll the circuit card(s) for these lines in the central office, be insistant.

Measure the voltage at other customers that would be in the same central office, if possible. Are they 38 or 48 volts?

Do you have another non-Toshiba system you could bring out to test those lines?

Is there another office close enough you could run a temporary 4 pair cable with their lines on it to the CX670.

No crying, phone people don't cry, they find solutions and get paid for it. Remember, doctors bury their mistakes.

Oh, do they have a non-AXE 10 switch in the same CO building that they could use to test?

For months and months and months I had a T-1 that would have lines refuse to drop. I kept pestering Paetec to roll the circuit card in the CO and no one would listen, no one. After six months they finally relented and rolled some card that processed 20 T-1s. One circuit would refuse to drop calls at random, ours. They paid for every service call we did after we asked them to roll the card and they refused.

Over here, (I cannot tell you where, hee hee)

When the line is not being used: 48 volts DC
When the line is being used: 12 volts DC
When the line is Ringing: approx 78volts AC