dbell@cup.portal.com (David J Bell) (04/12/91)
Reprinted (without permission) from the April, 1991 issue of Electronic Products, New Products announcements: >CHIP IDENTIFIES PHONE NUMBERS >The SC11210/211 Caller Identification Circuitis the first highly-integrated >analog front end that supports the Caller Number Delivery feature in a general >switched telephone network. It receives and decodes frequency shift key (FSK) >modem signals -- sent through telephone lines between the first and second >rings -- and allows the caller's number to be transmitted to a user's premises >while the phone is on-hook. >The device includes a differential-input buffer, a four-pole bandpass filter, >a FSK demodulator, a user-selectable energy detect circuit, and a clock >generator. The SC11211 version provides support for the power-down and >call-progress detect functions and has four energy detect levels. The >SC11210/211 operates from a +5-V supply and is available in 8- and 14-pin >packages. (About $2 each/10,000 --- available now.) >Sierra Semiconductor Corp. >San Jose, CA >Michael Friedman 408-263-9300 So there! That may even be enough information for you phone hardware hackers to design from. I haven't called about the availability of sample quantities, but Sierra should be open to individual sales, or may designate a distributor.. . (Of course, I have no affiliation with Sierra Semi., etc, etc, etc...) Dave dbell@cup.portal.com
dbell@cup.portal.com (David J Bell) (04/13/91)
More data acquired on Caller Number Delivery: The transmission occurs during the silent interval between the first and second power ring signals, into an *ON HOOK* line (no load, or >100k ohms). The signal is analog, phase- coherent, frequency-shift keying, with a logic 1 (Mark) at 1200 +/- 12 Hz, and logic 0 (Space) at 2200 +/- 22 Hz. The transmission rate is 1200 bps, data is serial, binary, asynchronous. Level is -13.5 dBm into 900 ohms. Looks a lot like a Bell 202 (1200 baud) half-duplex modem! With the interface circuit providing the demodulated serial signal, and a UART, you have the basic interface for Caller ID. Or, eliminate the UART and shift the level to RS-232 voltages, and input it directly to your PC. The encoding of the number is not clear yet, but should be easy to determine by experiment. Dave
sp@questor.wimsey.bc.ca (Steve Pershing) (04/15/91)
dbell@cup.portal.com (David J Bell) writes: > More data acquired on Caller Number Delivery: > > The transmission occurs during the silent interval between > the first and second power ring signals, into an *ON HOOK* > line (no load, or >100k ohms). The signal is analog, phase- > coherent, frequency-shift keying, with a logic 1 (Mark) at > 1200 +/- 12 Hz, and logic 0 (Space) at 2200 +/- 22 Hz. The > transmission rate is 1200 bps, data is serial, binary, > asynchronous. Level is -13.5 dBm into 900 ohms. > > Looks a lot like a Bell 202 (1200 baud) half-duplex modem! I believe that Sierra Semiconductor have just announced a Caller-ID chip, costing around $2.00 in 100 quantities. --- Steve Pershing, System Administrator : The QUESTOR Project: FREE Usenet News/Internet Mail; Sci, Med, AIDS, more : :===========================================================================: : Internet: sp@questor.wimsey.bc.ca : POST: 1027 Davie Street, Box 486 : : Phones: Voice/FAX: +1 604 682 6659 : Vancouver, British Columbia : : Data/BBS: +1 604 681 0670 : Canada V6E 4L2 :