The Telephone System
The main system unit from BBS Telecom.
System phones have alphanumeric caller ID displays
Purchase and installation
- Hands free intercom answer-back.
- Caller ID (Name and Number) Display
- At least one dozen extensions
- System programmable by touch tone phone. This way my home automation program can can program and configure the system.
I light of the above cost, I considering building my own system. However, there is a lot of hardware needed to implement a cross bar switch for 12 extension, 2 outside lines, 4 intercom conversations, and 2 signal sources (almost 100 switches). I would also need to build the hardware for the signal sources such as the ring and dial tone simulators. All this needs to be committed to PC boards (for reliability). I decided this was just too much work.
In order to prepare for the phone system I home ran Cat 5 cable to the various rooms in my home that didn't have a phone line. I took the opportunity to also run RG-6 into the bedrooms. The installation of the cable was preceded by installing a 2" conduit from the attic to my basement through a hollow chase in my home. I had found this chase while planning the installation of my central vacuum system. Since the ceiling in my basement (which I finished myself) has a drop ceiling, I could already access the hidden areas of the walls on the basement and first floor. After the installation of the conduit, I was thus able to run cable to any room in the house to the wiring closet in a corner of the house. There the phone/Cat5 lines were punched down into 66 type blocks. I then punched the leads of loose RJ11 jacks to the phone lines. These latter jacks allowed me to 'patch' the various extensions into the phone system's extension jacks, and were fastened to the side of the 66 type blocks.
The extensions wired are:
- Guest Room
- Master Bedroom
- Master Bath
- Secondary Bedroom 1
- Secondary Bedroom 2
- Secondary Bath
- Kitchen dining area/family room
- Rec Room
- Basement Bath
- Lab/Storage Room
Use of the system
You have reached the home of Agnes and Edward. If you are a
wish to send a fax, or want to leave a message, press '102'. Or else,
on the line or enter '0', and we will answer your call".
My home automation computer is now on its own extension. Since the phone node can seize the line, I have programmed the computer to answer the phone when its extension rings. I can then use the touch tones to send commands to it. This is better than the previous system where the computer starts processing tone commands when I enter a password sequence. This password sequence is intended to be an invalid phone number. This prevents the phone company from connecting me to an unknown location. However, the phone company answers with a beeping sound to alert the caller this number is invalid. The problem occurs when this beeping interferes with my computer's ability to recognize the touch tone command. This no longer occurs since I am having a quiet 'conversation' with my computer on my phone system. I can now also call in from outside and control the home without having to bypass my answering machine or without having to disturb any inhabitants in the home.
When I purchased the unit, I also wanted anyone inside the home to be able to connect to the door and speak with the visitor even before anyone had pressed the doorbell button. However, the unit would not perform this action, although this feature was mentioned in an on-line instruction manual for the door phone unit (page 6). This feature is similar to the "hands-free speaker phone" feature of the BBS key telephones. Over the years, we have come to like this feature very much. Thinking it was a problem with my installation, I used the DoorBell Fon in all kinds of configurations, but finally gave up after a few days. I then called and emailed the manufacturer, and to my surprise, a new version of the microcontroller (it is a PIC) was needed. Paul from customer support sent a new rev to me at no charge. I found phone support to be very good, but email support took a week before a response was generated.
I installed the new PIC, and 'bingo' it worked like a champ. Now anyone inside the home can connect to the door at any time to listen and speak by hitting '62' on a phone. I can also call from outside the home, and connect to the door phone, answering the door when I am at work or on travel. Worthington had the lowest price at $98. A pdf manual is available here from smarthome.com. More technical information on this unit can perhaps be found with a Google Search, or by using the link below.
The Door Phone unit from LocalPlex
The black "IVT" system phone that is
available from BBS comes in two flavors. The IVT-16D has an LCD
display that displays Caller-ID information (if the phone system has
option), and the IVT-16 (a.k.a. IVT-16N), which has no LCD
display. I purchased
one unit of the latter type from a person on ebay, and decided to open
the unit up to see if a display could be added.
LCD display on the IVT-16D. Apart from basic system status, it also displays
the Caller-ID information of the caller.
The IVT-16, which has no display. The location of the display has a black plastic plate.
When this phone is powered up, the 'MEM' LED (top middle) lights up as a power indicator.
Internal look of the IVT-16D. The LCD display is in the right half, on the top.
Inside view of the IVT-16, note the missing display although its connector (orange) is present.
The spacing of the pins on the connector is 2mm (0.075"), and there are 14 pins on it.
When the IVT-16 is powered up, its 'MEM' LED lights up, perhaps as a power indicator (since there is no display). When I unplugged the LCD panel from the IVT-16D, its 'MEM' LED lit up too! This implies that the firmware on both phones is similar, except the microprocessor detects the missing LCD, and lights the 'MEM' LED up. I then plugged in the LCD panel from the IVT-16D phone into the IVT-16, and the display showed text! This confirms that the firmware is functionally the same on both phones.
A closer look at the LCD panel on the IVT-16D shows that it has a '44780' microprocessor. I was really happy to see that as many LCD panels that are available on the surplus market use this controller. I thought to myself, perhaps I could simply purchase an LCD panel and upgrade my IVT-16? A look at my favorite surplus place (www.allelectronics.com) showed that they had a 20x2 display (model LCD-95) with approximately the correct overall size. It's price was $6.50.
I purchased two LCD displays (one spare), and found a 2mm connector to mate into the phone board. I then connected the display to the orange connector on the phone board (pin 1 to pin 1, etc). When I plugged the phone into the phone system. Success! The display lit up. Amazingly, the mounting holes in the panel lined up with the screw holes in the phone case. I then attached the display into the phone with some screws and covered the opening with a clear sheet of plexiglas.
The new display inside the IVT-16. I used a 30 pin connector to hold the 14 wires so that
it could be plugged into the back of the LCD display.
The finished installation of the display. The whole opening is covered with a clear plastic sheet
cut to the correct dimensions. It is nearly impossible to see the clear plastic in this picture.
Incidentally, I also purchased a 24x2 LCD display from All Electronics (model LCD-74), and since it already had a 2 mm connector on it, I plugged it into the phone, and that worked also. However, the extra width prevented a good way of mounting the display into the phone. I presume the extra eight characters on the display would remain blank. This compatibility does not surprise me as the 44780 controller is addressed the same way regardless of the size of the display.
So to summarize, the overall upgrade project cost is about $7.00 (with shipping, etc), and one 2 mm connector from my junk pile. On the Lee Phones website, the IVT-16 costs $135, while the IVT-16D costs $165, so I saved myself a little bit of money. As we can see, it is easily performed using commonly available components.
Tips and Tricks
According to BBS technical support, there is a NiCad battery inside the system unit. This allows the programming to be preserved across power failures. Since the battery is float charged, It will need to be replaced in a few years.
- May 1997 - Installation of the main
- July 1997- There has been a complete cessation of those annoying telemarketer calls! The auto attendant message is able to make it clear that they are not welcome.
- November 2001 - Added door phone from 'Local Plex'.
- October 2003 - Purchased a spare
IPS416 unit (with the highly
desired Caller-ID option) for $127 on ebay. A real good
deal compared to the price I paid for the original unit ($900,
ouch). The spare unit will be used if the original is damaged due
to lightning or other major surge. These units are in
surprisingly high demand on ebay, and I had to wait for several months
before I was fortunate enough to purchase one at this price.
Label on the back of the second unit from ebay. The "CID" on the label
(and a label on the CPU) confirms it has the Caller-ID option.
If the unit does not have Caller-ID, the CID will be "MVX" (example)
- November 2003 - Purchased two IVT-16D alpha-numeric keyphones for
$42 each on ebay (these phones normally auction for at least
$75). Lee phones,
who has the best on-line price for these phones sells them for about
- February 2004 - Purchased an IVT-16N phone (no LCD display) on ebay for $36 (+ shipping), and added a display (see above). So currently I have 6 key phones with alpha-numeric display, and 2 without. Specifications on the display:
- Optrex #DMC-50218.
- Viewing area, 3.26" x 0.7".
- Module size, 4.58" x 1.46".
- 5 x 8 dot
- Prepped with 7 x 2 dual-row header, 0.1" spacing.
- CAT# LCD-95. Price: $6.50 each
- October 14, 2004 - Purchased an IVT-16N (no LCD display) on ebay for $28 (+9 shipping). Display added as above.
- October 15, 2004 - Purchased an IVT-16D on ebay for $0.01 (+$12
shipping). What a great buy.
- October 23, 2004 - Purchased an IVT-16D on ebay for $1.57 (+$14 shipping). Now I have plenty of spares.
- December 5, 2006 - Purchased two IVT-16D on ebay for $41 (+$9).
- November 13, 2007 - Problem with door phone unit. It
stopped working. When I connect to the door unit from an internal
phone, I get a fast busy signal. After an investigation, I find
that the problem is a simple wire break to the door unit. Thus
the main box reacts by sounding a fast busy in this case. I
recall that when I purchased the unit, they sent me a custom chip that
makes it compatible with phone systems. The fast busy does not
occur with the original controller chip. The manufacturer is still around,
and I contacted them to purchase a spare controller chip (Model #N8-NC)
for $10. In general, the entire phone system is running just
fine. No issues.
- BBS Telecom Corporation
- Panasonic Corporation
- HomePhone.com. Home page for the DoorBell Fon.
- Communications Technology Review write up.
- Search for BBS units for sale on ebay.com.
- Lee phones site for
purchasing new items.
(c) Edward Cheung, all rights reserved.