VIC2-2E/M Connectivity Help

Answered Question
Aug 12th, 2010

Hi All,

I have a client that has a Public Announcement system installed. We used an E/M card to interconnect the PA system to the voice gateway on site.
Everything was working fine with the below config:

------------------------------------
!
voice-port 0/1/0
auto-cut-through
type 2
signal immediate
cptone ZA
!
dial-peer voice 9999 pots
description PA_System
destination-pattern 9900
no digit-strip
direct-inward-dial
port 0/1/0
forward-digits 0
!
------------------------------------

Here is the wiring guide from the PA System:
http://www.photosite.co.za/uploads/594PA.jpg

I used this pinout configuration:
http://www.photosite.co.za/uploads/741pinout.jpg from : http://www.cisco.com/en/US/tech/tk1077/technologies_tech_note09186a00800942ef.shtml

I used pins 1,8 for signaling and 4,5 for audio.

Problem
-------
After  there was a power failure onsite, the E/M port didn't want to send an  'open signal' to the PA sysem anymore, but the call still proceeded and  indicated connected.
After configuring the 2nd E/M port and changing the dial-peer to send the call to it, it worked again. 

Could there be an issue with the power that's being supplied from the PA system or incorrect wiring between the 2 devices ?

This problem happened on 2 sites at the customer.

I have this problem too.
0 votes
Correct Answer by philip.e.denton about 6 years 5 months ago

Read the input capabilities in the specs you sent me and you'll see: "Telephone paging input: Push-in terminal block(*6)"

This usually means you need a gateway to supply FXO service to the paging adaptor.  If you have no FXO ports available you can get away with FXS ports and an Adaptec PagePal or TAM-B, although those devices require A/C power.

It is important to note that FXS ports are more prone to supervisory disconnect issues than FXO, meaning they can hang open after pages are complete and don't release the port back to the gateway.

In summary, if you can get a VIC-2FXO or VIC2-2FXO (preferred) in your gateway and punch it to the "telephone paging input" on the back of your PA system you should be in good shape.

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Overall Rating: 5 (1 ratings)
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Felipe Garrido Mon, 08/16/2010 - 13:40

Philip,

Sounds like a possible hardware problem. If the same configuration and equipment work on one port but not the other, than it sounds like there is a problem with that particular port.

-Felipe

Salvo_Phl Mon, 08/16/2010 - 23:23

Thanks for the reply Felipe, but I know the problem is with the hardware.

The system was working fine on initial port before a power failure onsite, but now the E/M port doesn't send the 'switch' signal to the PA device anymore.

I was wondering if someone could assist in letting me know if I've used the correct pinouts according the above links.

Thanks,

Philip

brendand05 Tue, 08/17/2010 - 23:35

Because of the power failure I would recommend replacing the WIC.

A power failure is going to re-wire pinouts that were previously working

philip.e.denton Wed, 08/18/2010 - 06:00

Also, I've never run into a situation where I was required to use a VIC-2E/M for analog paging integration.  Usually I used a TAM-B or Adaptec PagePal with FXO or as a last resort FXS (with TAM-B).  Is it the separate control and audio circuits on your PA system requiring your use of the E&M port?

Salvo_Phl Wed, 08/18/2010 - 06:13

Hi Philip, thanks for the reply.

Quote:

Is it the separate control and audio circuits on your PA system requiring your use of the E&M port?

Yes that would be correct as far as I know.

I was told by the technitian from the PA system side that their device sends out 30v of current over the control circuit. I'm not too clued up about E/M configurations ect, so not sure what the E/M card can handle voltage wise ?

Since my 1st post, the 2nd port has also ceased 'switching' to the PA system, so I'm busy getting it replaced by the supplier, but need a solution for when it's back....

Thanks,

Phil

philip.e.denton Wed, 08/18/2010 - 07:42

Philip, I'm curious why the PA system would be sending voltage over the control circuit?  One would think the VIC would originate voltage on the control pair to signal to the PA to listen for a page on the signaling pair.  Can you tell us the exact model number of the device you're integrating with?

Also, what made you choose 2-pair Type II signaling for your interface over one of the other configurations?

Salvo_Phl Wed, 08/18/2010 - 08:10

I agree, not sure why there is a current comming from their system... ? I will get back to you with the System Model number.

It was just a case of trial and error really.... I got to a point that the configuration worked as it should and I figured that that was that.

Is there any configuration commands I could use such as 'impedence' perhaps to regulate the voltage recieved by the card ?

philip.e.denton Wed, 08/18/2010 - 08:22

Possibly but I'm not an electronics expert and as I said before, my paging integration experience lies mostly with FXO/FXS, rather than E&M.  I'm curious to get the PA model number though, as that will hopefully lead us to some detailed schematics and integration documentation, including what port-level configuration is required.

PS  I'm reading up on the Adaptec PagePal to see if it will work in this scenario...

Attachment: 
Correct Answer
philip.e.denton Thu, 08/19/2010 - 04:57

Read the input capabilities in the specs you sent me and you'll see: "Telephone paging input: Push-in terminal block(*6)"

This usually means you need a gateway to supply FXO service to the paging adaptor.  If you have no FXO ports available you can get away with FXS ports and an Adaptec PagePal or TAM-B, although those devices require A/C power.

It is important to note that FXS ports are more prone to supervisory disconnect issues than FXO, meaning they can hang open after pages are complete and don't release the port back to the gateway.

In summary, if you can get a VIC-2FXO or VIC2-2FXO (preferred) in your gateway and punch it to the "telephone paging input" on the back of your PA system you should be in good shape.

Salvo_Phl Thu, 08/19/2010 - 05:07

Cool man ... I'll try get a hole of a FXO Card to test

Thanks for all the help and information!

Oh and since you brought up the Superviory Disconnect problem, I actuall had that at another client, that was using a 4 port FXO card, and I had a problem if you terminate the incomming call before a user had ansered, the phone will ring for another 6 seconds before disconnecting.

Couldn't find a solution at the time though...

Any idea's ?

philip.e.denton Thu, 08/19/2010 - 05:20

Well... don't rate me yet.  I was reading over the manufacturer's technical specs for your specific PA hardware and they seem pretty hell-bent on that 2-pair setup, even for telephone paging input (which is pretty strange imho).  I feel pretty confident about my answer but I'd suggest you call the vendor directly and verify with them exactly what you need to do to complete the integration.  Usually they're really helpful and I'd rather us be 100% sure about what is needed than 99%.

With that other FXO issue did you have the  FXO ports going out to the PSTN?

Salvo_Phl Thu, 08/19/2010 - 05:36

Haha...well, i'm further along to find the problem than before.


The PA technitian did attempt to get information from the supplier with regards to intergation with a Cisco Router, but they had NO info.

WIll try obtain a loan card FXO to test.



Quote:

With that other FXO issue did you have the  FXO ports going out to the PSTN?

Yes that's correct.

Paolo Bevilacqua Thu, 08/19/2010 - 05:38

It's actually quite reasonable that PA maker insists on 2 pairs connections, when they do not integrate an hybrid decoupling circuit or can not take loop and ring currents that an FXS normally provides.

These adapters can bought from various sources in case you need to patch phone and audio interfaces together, a common occurence since many decades.

Paolo Bevilacqua Thu, 08/19/2010 - 08:43

I am not familiar with TAM products. However, if they say it's made to interface FXO to audio interface, it will work.

Salvo_Phl Wed, 08/25/2010 - 01:36

Hi Philip,

This is the document the client used to scope the E/M Card for their PA solution :

http://www.cisco.com/en/US/tech/tk652/tk653/technologies_configuration_example09186a008015094e.shtml

So according ot the doc :

T1 (Pin 4) ---------------- Microphone audio input 
R1 (Pin 5) ---------------- Microphone audio input
E lead (Pin 7) ------------ Push-to-talk control input
Ground (Pin 8) ------------ Push-to-talk control input

Still waiting on an RMA for the card.

Phil

philip.e.denton Wed, 08/25/2010 - 05:45

Well Philip, I definitely can't argue with that.  When you configured your E&M ports did you ensure you set your ports up as "two wire, type 5, with immediate start operation" (as outlined in that document)?

! 
voice-port 1/0/0 
 operation 2-wire    

!--- Only use pins 4 and 5 for audio.

 type 5                

!--- Type 5 operation, the most basic mode.

 signal immediate      

!--- Immediate start operation.

 auto-cut-through     

!--- Send immediate answer back to the VoIP network. 

! 
Salvo_Phl Mon, 08/30/2010 - 07:40

Thanks Phil, Pretty sure it is configure as above, but will confirm once I have the RMA back.

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