Patton SN4112 2-FXO with older paging system

[DedTreeJig]

Hello,

We currently using a Grandstream GXW4104 FXO with our older paging system which works, however I am trying to replace it with a Patton SN4112 FXO and I'm running into an issue.

Current Setup
The GXW4104 FXO was setup using the configuration generated by 3CX (v15.5.15502.6), the Grandstream connects directly to an ATT PagePal (which connects to the paging system). An outbound rule is setup to route 66 through the Grandstream stripping out the 2 digits. In this configuration the paging works, the PagePal picks up, plays a tone and then plays the page.

If I replace the Grandstream with a Patton SN4112 FXO also using the configuration from 3CX, the PagePal picks up, plays a tone but then the Patton immediatly disconnects from the PagePal.

I tested the Patton with pots lines, it works fine.

The ATT PagePal is a seriously old peice of equipment but I am hoping someone may be familiar with it or knowledgable enough to know why the Patton isn't working.

I had originally planned to use a Snom PA1 but there is a large impedance difference between the PA1 and the input on the paging system. If I recall correctly the PA1 is 8 ohms and the input on the paging system is 220k ohms.

Any help would be appreciated.

 

[leejor]

The fact that you are using an FXO means that the paging system acts as a PSTN line (providing 24 to 48 vdc). This also mean that you should be able to connect an analogue phone to the input, for testing if necessary. I would first check the 3CX Activity Log to see which end is dropping the call, or if there is anything that may give clues as to why it drops. Check the voltage coming from the paging unit. If it is 24 volts rather than 48, there may be a setting that has to be changed to accompdate that. Check to see if the paging unit is set to ground start. If so, something else may need to be changed in the Patton.

 

[DedTreeJig]

@leejor
Thanks, those some great things to check.

 

[eddv123]

You can also troubleshoot and get a real time log from the Patton device itself (via command line interface). This can be done with the following commands:

enable
show running‐config
debug call‐router
debug call‐control
debug fxo
debug ccfxo
debug context sip‐gateway signaling detail 5
debug context sip‐gateway transport detail 5
debug context sip‐gateway error

Please feel free to send them over if you would like them looked at, you can also contact Patton support, they are normally very helpful.

 

[DedTreeJig]

@eddv123
Thanks for the additional tips.

I hope to get back to working on this later in the week. I'll post my findings.

 

[cobaltit]

If you didn't reset the Grandstream I would change the voltage settings. It sounds like the Patton is responding to voltage/current changes (I forgot the exact terminology) but basically what it sees on the line is causing the Patton to hang up. There may have been some manual configuration of those settings on the Grandstream or possibly the defaults are just different than what is on the Patton.

 

[eddv123]

@cobaltit, I think you maybe referring to the gain settings which can be found under PSTN profiles: https://www.patton.com/support/kb_art.asp?art=445&