[VoIP] [off VoIP] Ernest Telecomm 7D-3 Payphone

Donald Froula dfroula at sbcglobal.net
Tue Sep 4 08:30:14 CDT 2007 

Well, some kind collector sent me a .pdf manual for a
similar (ETX) payphone. He also sent along the
software needed to program the phone using a 1200 baud
modem.

Another individual sent me a guide to wiring up a
standard 14-pin LCD module to the "LCD" connector on
the circuit board to allow keypad programming.

I decided to go the modem programming route. I had a
NIB "old" MultiTech modem that I decided to try to
use. The software (written in Visual Basic) wants to
see a real Hayes modem and has the original Hayes
command set hard-coded into some parts of it. The
software did allow settting up custom initialization
strings. I found the commands to lock the modem to
only try 1200 baud connects and to disable hardware
handshaking. After reprogramming the phone ID number
with the keypad (blind, without the LCD) I was able to
connect and read back the stored settings over
Asterisk and two ports on a Linksys PAP2 ATA.

The phone uses a pre-loaded rate table that is
customized to the area code and exchange where the
phone is installed. The rate table classifies any
dialed number into local, inter-lata, intra-lata,
inter-state, and international. The classification is
all relative to the area code and exchange where the
phone was installed. This is problematic when using
the phone in another location.

This rate table file can be uploaded and downloaded,
but not edited by the software. Apparently, one had to
buy a customized table from Ernest Telecom, now out of
business. I looked at the uploaded rate table with a
hex editor, but there is no readable text that could
be edited inside.

There are rate override settings to allow one single
rate for all 7 digit and another set for all 10 digit
phone numbers. However, the predefined local area
codes and exchanges override the overrides!

The answer was another function in the phone called a
CSN (Customized Special Number) table. This allows
redifining the rate band for any area code, exchanges,
specific phone number, etc. Wildcard characters are
allowed, so it is quite flexible. I used this to
redefine the band all of the area codes/exchanges
predefined as local, then defining a new set of local
exchanges. This worked, although it would have been
great to have the software that actually generates a
new rate table.

An interesting feature of the phone is the ability to
define a "211" refund number. The phone will make a
free call to the defined "211" number. The person
answering the phone can query the phone via DTMF to
check the last call dialed, the amount collected, and
the duration of the call. The "operator" can then
remotely actuate the coin return and/or issue a refund
amount that the phone will apply to the next call from
the phone.

The owner can also check the coin box balance and
reset it remotely or from the keypad.

I have this all working on Asterisk with a custom
context.

The phone is completely line-powered. It seems quite
happy when connected to a Linksys PAP2 ATA, even
though the voltage is not 48VDC.

The phone uses a coin detector switch that has three
slots, matching the three slots output of the coin
sorter. As the sorted coins drop through one of three
slots, it closes a contact that tells the circuit
board what has been deposited. The switch occasionally
jams when a coin slips between the wall of the slot
and the little actuator lever. Apparently a new unit
is available that has wider actualtors to avoid this.
It is a real pain to fix these jams, so I will order a
new switch from payphones.com. All these coin path
parts appear to be standard across brands of COCOT.

There are pins on the board for a ringer, although
none was installed. The ringer capacitor is on the
board. I hooked an old mechanical ringer to the pins
and it rang fine.

Now to put it in the family room and try to collect
some cash from the family for a "second line"!

Don

--- Steph Kerman <stfkerman at jps.net> wrote:

> Don,
> 
> I checked.  He does not have any info on this.
> 
> Steph
> 
> On 8/25/07 Steph wrote:
> 
> I'm copying this to a friend who had a COCOT
> business some years ago.  I
> don't know whether he can help but I'm sure if he
> can he will.
> 
> Steph
> 
> Donald Froula wrote:
> > I picked up an Ernest Telecomm 7D-3 single-slot
> COCOT
> > payphone today. There is a programming switch on
> the
> > board in the phone that seems to put the keypad in
> > programming mode, but I get no voice prompts or
> any
> > other indication, other than DTMF when I press the
> > keys.
> >
> > The board is labeled "Ernest D3". 
> >
> > Does anyone have programming instructions for this
> > beast?
> >
> > Thanks,
> >
> > Don
> > --- Steph Kerman <stfkerman at jps.net> wrote:
> >
> >   
> >> Mark,
> >>
> >> Do you have the detailed description of the 1D
> type
> >> CTS?
> >>
> >> Steph
> >>
> >> Mark Rudholm wrote:
> >>     
> >>> Steph Kerman wrote:
> >>>   
> >>>       
> >>>> Mark Rudholm wrote:
> >>>>     
> >>>>         
> >>>>> Something I've noticed with my D phones is
> that
> >>>>>           
> >> they mute the coin 
> >>     
> >>>>> tones much more than my C phones.
> >>>>>       
> >>>>>           
> >>>> I noticed recently that the coin maintenance
> >>>>         
> >> practice specifically says 
> >>     
> >>>> the Ds mute completely and the Cs not.
> >>>>     
> >>>>         
> >>> If you're in a quiet place, you can hear the
> coin
> >>>       
> >> tones on a D
> >>     
> >>> set, but just barely.  I assume it's
> unintentional
> >>>       
> >> (like the
> >>     
> >>> slight amount of pulse clicking you can hear on
> >>>       
> >> most rotary
> >>     
> >>> phones despite the receiver being "muted").
> >>>
> >>> If you know of a way to change the "muting" to
> >>>       
> >> something more
> >>     
> >>> like the attenuation applied by touch-tone dials
> >>>       
> >> when sending
> >>     
> >>> DTMF signals, I'd be interested.  Presumably
> >>>       
> >> there's a switch
> >>     
> >>> opening somewhere in the phone that could be
> >>>       
> >> defeated with a
> >>     
> >>> jumper or resistor (non-permanently).
> >>>
> >>>   
> >>>       
> >>>>> There are some other minor differences. For
> >>>>>           
> >> example, if you put a coin 
> >>     
> >>>>> into a C phone while it is on-hook, the phone
> >>>>>           
> >> will pause and then 
> >>     
> >>>>> return it. If you do that on a D phone, the
> coin
> >>>>>           
> >> will sit on the 
> >>     
> >>>>> hopper until you go off-hook and then on-hook.
> >>>>>       
> >>>>>           
> >>>> That's interesting.  Never noticed.  I have C
> and
> >>>>         
> >> E sets but haven't 
> >>     
> >>>> played with them much.  I'd like to have an A
> too
> >>>>         
> >> but so far don't.
> >>     
> >>>>     
> >>>>         
> >>> I'd like to have an un-modified three-slot. 
> >>>       
> >> Unfortunately,
> >>     
> >>> those don't seem to exist anymore.
> >>> _______________________________________________
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> >>> Project Web Page: http://www.ckts.info/
> >>>
> >>>   
> >>>       
> >> _______________________________________________
> >> VoIP mailing list
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> >> Project Web Page: http://www.ckts.info/
> >>
> >>     
> >
> > _______________________________________________
> > VoIP mailing list
> > VoIP at lists.ckts.info
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> >
> >   
> 
>

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