Old Panasonic PBX (308, 616) Ringing

[TelePlay]

Proprietary telephones don't cascade.  Why would they?  The proprietary sets don't use the A.C. ring signal at all. They ring on digital command by the CPU.  The reason for cascading the analog phones is to spread or average the electrical load of ringing over time to avoid the higher instantaneous power consumption.
The ringing of proprietary stations is accomplished with the telephone speaker in the main unit, requiring much less power.

Thank you for clarifying the operation. That is what I thought was the reason and it makes perfect sense. And as poplar1 said, only those who want to program a 616/308 own the correct proprietary phone. The rest just use these systems to test phones or activate their collections. So, now we know.

[mentalstampede]

The proprietary phones I have are KX-T7736.  Is it the phone sets themselves that create the cascading effect.

That must be it. The cascading ring is done with non-proprietary phones to ensure there is adequate power to operate mechanical ringers. It makes sense that it would not be necessary to do so with the electronic ringers present in the proprietary sets.

[Mmg577]

I really appreciate all the responses.  It's definitely a mystery. I know for a fact the older Panasonic PBX and proprietary phones did this.  My family had one (I wish they had never gotten rid of it), but it was a KX-T1232 with the KX-T123230 phones. Given this, I wonder if it has something to do with those really old proprietary phones.  I only have KX-T7130 and KX-T7736 to test.  I guess it might be worth buying an old one of eBay.   

[oldguy]

Mine are version 3. I only have old phones hooked up. That may be the issue.

[Mmg577]

Mine are version 3. I only have old phones hooked up. That may be the issue.

When you say you only have old phones hooked up, do you mean old proprietary phones like the kx-t61620 or kx-t123220? Or old non-proprietary phones?  Here is a pic of the phones I am thinking of.   

[oldguy]

No, I mean WE 500s, 2500s, princess, trimline, etc.

[Phonesrfun]

I really appreciate all the responses.  It's definitely a mystery. I know for a fact the older Panasonic PBX and proprietary phones did this.  My family had one (I wish they had never gotten rid of it), but it was a KX-T1232 with the KX-T123230 phones. Given this, I wonder if it has something to do with those really old proprietary phones.  I only have KX-T7130 and KX-T7736 to test.  I guess it might be worth buying an old one of eBay.   

I think the 1232 is altogether a different animal than the 308 and 616.

[unbeldi]

I think the 1232 is altogether a different animal than the 308 and 616.

The 1232 systems indeed use a different design strategy.  They are modular so that a customer can start with a system of small configuration and expand it as need arises in a growing business, without having to replace the entire telephone system, and without having to buy a full system at first that has mostly unused capacity.   System replacement times are critical times for vendors, because it opens the possibility that they lose the customer to another vendor by comparison shopping. With an expandable system, the upgrade cost and learning curve, etc, are kept at a minimum and the customer is locked in.

The modularity in design requires changes in logistical layout of the system.  The line cards now come in groups of eight ports (IIRC) and each group adds additional CO lines.  This changes not only the way the station numbering is arranged, and how ringing groups work, but also things like power-fail cut-through from the CO lines to the stations. On the smaller systems, the CO lines cut through to the first group of stations directly, but in the 1232 the CO lines cut through to stations on their respective line card, so it is not the first 'n' stations of the system.

But the basic technology features, the semiconductor base, are the same in them.