sundance-communications.com/forum Forums TDM Business Telephone Systems Vodavi Telephones & Systems STS and Polycom Sound Station not playing together

A customer has started having issues with Polycom Sound Stations (P2200-16200-001). Four of them are on a SLIB-4 card (STS), one is on the built-in analog extensions. The four on the SLIB have very low outgoing audio that fades in and out. I did some remote trouble shooting with someone on site:

Install new SLIB card- no change

Tried 2500 type set on one of the analog jacks-sounds good.

Plugged Polycom directly into POTS line, sounds good.

A working Polycom on another system in the same building sounds horrible, when placed on the system in question.

History: system was moved about 6 weeks ago, no problem until last week.

Changed from ILEC to CLEC last Friday, they say problem started before that.

Sounds like evil spirits at work and I am stumped. I am going to go by there and take some loop-current measurements, but I suspect that's not the problem.

Any ideas would be greatly welcomed,

Thanks
Vernon Hobbs
Seaboard Comm.

Check off hook voltage on the SLIB versus the built in ports. I believe you'll find the voltage to be lower. You might try installing the 2 port SLT adapter and see if it resolves your problem.

I've had the same issue with Polycoms and the SLA seemed to work better.

Thanks, I'll be taking voltage/current readings tomorrow. The mystery here is, they did work for several years, now they don't. Some of them are further away from the equipment room after the move.

Vernon Hobbs

Since you are going back to check voltages, try doubling up the copper at the farthest one and report back. If distance is a factor, this could help.

Also, did you use a Cat 5 cable for voice? I am going to post a related question on this subject that I have never asked before and put it in the cabling category.

Well, current at a not working Polycom was 25mA, current at working one was 29mA. All ports supplied around 23 volts on hook.I thought about doubling-up pairs, but the entire wiring job is terminated on patch panels. Maybe I could rig some sort of adapter. It is CAT 5, the wiring was already in place, another vendor made what changes were necessary and did the certifications. I think I'm going to take an Avaya module over there and see if that will boost the loop current up.

Vern Hobbs

25ma should be plenty. Should be pretty easy to rig something temporary to see if doubling the pairs will help, just use back to back jacks and patch cords. I'd use full pairs like w/bl pair for the tip w/or pair for the ring.

It's not a loop current issue. Funny thing is, doubling, tripling , quadrupling pairs made virtually no difference in the current. The range was from 24.9 to 25.2 mA. I'm at the point now where I'll have to move the SLIB-4 card around to see if that changes anyything.


Vern Hobbs

Sounds like something inherit in the SLIB cards. Deltron may have your answer.

Try putting a phone with a built in speaker on one of these locations. My guess is they would do the same thing as the Polycom. There must be some kind of delay in the SLIB's, which doesn't play nice with speaker phones.

Thanks,
Deltron? Thing is, they did work up until the move. Vertical seems to think it could be an issue with the EKSU or the interconnecting cable to the BKSU.
Thus, I'll be moving the SLIB card into the BKSU after hours today.
In 25 years, this is the oddest thing I've ever seen, (except for a 50 wire nut splice Sparky did on a 25 pair cable).

Vern Hobbs

Deltron's post.

In your original post you said the customer stated they had problems at the original location also. Did that change?

I haven't put a Polycom on one so I really don't have the experience as some of the other posters on this issue. From what you're saying there seems to be an incompatibility between the 4 station SLT cards and the Polycom as you said the one on the built in 2 port SLT works find. Be interesting to see what happens when you move it to the first cabinet. Thanks for keeping us informed.