sundance-communications.com/forum Forums Other TDM Phone Systems ESI Telephones & Systems IVX E-Class FXO line hanging open

We have a customer with an E-Class that has a line which hangs open a few times a week. The only way to release the line is either to do a power reset of the IVX or to disconnect the line from the carrier equipment.

They have now had this issue with 2 separate carriers and 2 separate line cards. So I have to eliminate carrier signaling and line card ports as being our cause. Is there possibly some timing issues going on noise?

Anyone else had this issue or anything similar?

System configuration as below:
IVX E class 128
1 D12 (6 FXO and 12 digital extensions)

ESI Tech support should be able to look at debug and tell you under what circumstance the line locked up. If it was a call into the autoattendant, you could try checking the branch timeout option to make sure it goes to disconnect (ID 9999)

A D12 module is 12 digital ports ONLY. Do you mean a D612 module providing 6 CO lines and 12 digital ports?

First things first. Have you measured the on and off hook voltage and the off hook current? The E class has a very tight tolerance and anything above 35 ma will cause the exact conditions you describe. You can reduce the current by inserting a current regulating device from Sandman or you can add resistors. At one time, ESI provided "Hot Cards" which had the regulators built in.

If it's not too high line current, then you may want to check if the CO is providing CPC.

Rcaman

This system does not have a branch timeout option, but the no entry timer is set for 500. I hope to catch it hung when i go with the sandman current limiter and i will put a buttset on the hung line and see if it is AA or just dialtone.

Sorry you are correct my goofup there it is a 612 card.

To be safe i will go ahead and order a Sandman device.

Not to be pushy, but you need to take a VOM or other testing device that can measure DC current and measure the line first. If you do not need the Sandman devices, why spend the money? You may also detect a low current condition which can cause line release problems as well. The "expected" range of line current, when the CO line is off hook is 25 to 35 ma. Anything lower or higher will cause many problems.

Do a little troubleshooting and save yourself some time and money.

Rcaman