======================PHONE_CIRCUITS======================================= Telephone switch to connect and disconnect the phone from network. called the hook switch. connects when you lift handset. 8-ohm speaker of some sort microphone.just carbon granules compressed between two thin metal plates. dial simple phone by rapidly tapping the hook switch all telephone switches still recognize "pulse dialing" If rapidly tap the switch hook 4 times, phone company's switch understand dialed a 4, modern telephone also includes a bell so it can ring intercom system using two telephones, 9-volt battery (or some other simple power supply) and a 300-ohm resistor connection to phone company consists of two copper wires green wire common, red wire 6-12 volts DC at 30 milliamps simple carbon granule microphone, modulating current ring_signal is a 90-volt AC wave at 20 hertz. [Fun fact - hand crank on old-fashion telephones used to generate this AC wave and ring bell other end!]. -------------------------------------------------------------------------------------- dial tone sound is combination of 350 hertz tone and 440 hertz tone dialing sounds made of pairs of tones, as shown here: 1209 Hz 1336 Hz 1477 Hz 697 Hz 1 2 3 770 Hz 4 5 6 852 Hz 7 8 9 941 Hz * 0 # busy signal made up of a 480 hertz and a 620 hertz tone, with a cycle of 1/2 second on and 1/2 second Telephone Bandwidth below 400 hertz and above 3,400 hertz are eliminated. telephone network starts in your house. pair of wires runs from box at road to box ("entrance bridge") at your house. pair of wires usually using red and green wires second pair is usually yellow and black inside house. -------------------------------------------------------------------------------------- Limits Common battery v -48 volts DC (onhook) -4 to -105 volts DC Common battery v -6 volts DC (off-hook) 20 to 120 mA Operating current 20 to 80 mA 100 to 400 ohms Resistance of phone 300 ohms 0 to 3,600 ohms Subscribe loop resist 0 to 1,300 ohms 17 dB Loop loss 8 dB not applicable Distortion -50 dB total 16 to 60 pps Ringing frequency 20 PPs 40 to 130 volts rms Ringing voltage 90 volts rms -------------------------------------------------------------------------------------- DTMF Dual Tone Multiplexed Frequency, tones heard while pressingkeys on telephone. Each key is a mixture of two {1} = 1209 Hz and 697 Hz mixed together: 1209Hz 1336Hz 1477Hz 1633Hz ABC DEF 1 2 3 A 697 Hz GHI JKL MNO 4 5 6 B 770 Hz PRS TUV WXY 7 8 9 C 852 Hz oper * 0 # D 941 Hz -------------------------------------------------------------------------------------- need 12K-15K volts AC (50/60) Hz at say 20-30 mA. neon sign (luminous tube) transformer usual source -------------------------------------------------------------------------------------- phone line rings there's 90 V RMS AC at 20 HZ on the line Phone In-Use Light >>---------+------+---->> phone line | | | o | / | / momentary switch | | | / | \ 1200 Ohm | / -----____| / \ /___\ SCR | / \ 600 Ohm / | ^^ ----- // / \ // /___\ LED | | >>---------+--------->> phone line -------------------------------------------------------------------------------------- Phone to audio interface (SSI202 input) .22 uf 10k pot 400v ||(----> Phone line tip o---)(--)||( <---o to SSI202 input )||( > Phone line ring o-------)||(----o---o ground Phone Off-Hook Indicator Phone Information voltage across the telephone line shows (typical numbers): On Hook: 40 to 50 VDC Off Hook: 4 to 6 VDC Ringing: 100 VAC standard" impedence of a telephone off-hook, is 680 ohms. Hanging a 680 ohm resistor across the telephone line will drop the voltage from 48V to about 5V, causing the line to go "active". This is how HOLD switches work. phone rang' indicator light This, will detect the ring signal, energize the relay which latches up, and the LED comes on and stays on till you push SW. ____ tip o--CC---RR----o---D<-o---o-->D----^ ^----o-----+ | | | SW | | | | | | | \-/ |- R|| B- LED Z C L||......... A | | |+ Y|| __.__ T+ R | | | +--o o---+ | | | | | | ring o------------o------o---o-----o------------+ CC=.47 uF 200 V. capacitor RR= 3k (depends on relay) D = 200V diode ( > < direction od diodes) Z = 12 zener RLY= any small relay SW= normally closed switch K = relay's contacts BAT= 9 V. battery R = 500 ohm (for LED) C = some (10) uF capacitor Get 3v relay... Set it up as follows: Audio Isolation Transformer To <--)||(---------------------+ )||( | <= Relay Contacts Speaker <--)||(---+ +--------o/ o 600ohm | | mmmmm DC 3v Relay Coil | | | | RED -----------|----+-------+ +-> | GREEN -----------+---------------------> To Dispatcher's Phone | | -+- indicates a connection, --- is not connected. | | DC current through phone and it transmits and receives audio. two phones and a current source (about 25mA) all in series give you a talking circuit. To ring bell you need 90V (RMS) 20Hz AC into phone (nominally) down to about 40V)different frequencies won't. can't ring the phone at 60Hz. This is what I have come up with: + | | - +---+------ - --+-||||---/\/\-+-- - ---+-------+ | | | | | R | | | | | | 24V | | | | --- | | --- | | | | +-||----------+ | | | | --- Sonalert C Sonalert ---| | C | | C | +-||-+ +--||---+ | _|_, _|_ | | / \ 15V 15V \ / | PHON -+- Zener Zener `-+- PHONE | | | | | | | | +----+---------- - - - ----------------+-------+ set R to give you a talking current (both phones offhook) 25mA. capacitors C about 0.47uF. phones are onhook present an open circuit When both phones are offhook very low resistance -------------------------------------------------------------------------------------- Telephone Power? Any substantial power drain from their lines WILL be detected. If it's large, the phone switch will conclude that you've dropped the phone in the bathtub or something like that, and will disconnect your line will check periodically to see if be reconnected). If it's small, switch report it to service people as a possible line problem, to be investigated before it causes a complete failure... and if they investigate and find that you're to blame, they will probably send you a bill for time current you can draw without eventually having it noticed is very small. Hold function for Telephone +-------+------+ R1 = 2.2K | | | R2 = 1 K -| SW R | R3 = 47 ohms | 1 | SCR = 2N5064, TIC47, or MCR104 | | | R LED | Well, that's it, just remember that 2 | | the cathode of both the SCR and the | | +----RING (Red) LED are towards bottom. +------SCR | | +----- TIP (Green) R | | 3 | | | | | +-------+------+ ======================PHONE_CIRCUITS======================================= Telephone switch to connect and disconnect the phone from network. called the hook switch. connects when you lift handset. 8-ohm speaker of some sort microphone.just carbon granules compressed between two thin metal plates. dial simple phone by rapidly tapping the hook switch all telephone switches still recognize "pulse dialing" If rapidly tap the switch hook 4 times, phone company's switch understand dialed a 4, modern telephone also includes a bell so it can ring intercom system using two telephones, 9-volt battery (or some other simple power supply) and a 300-ohm resistor connection to phone company consists of two copper wires green wire common, red wire 6-12 volts DC at 30 milliamps simple carbon granule microphone, modulating current ring_signal is a 90-volt AC wave at 20 hertz. [Fun fact - hand crank on old-fashion telephones used to generate this AC wave and ring bell other end!]. dial tone sound is combination of 350 hertz tone and 440 hertz tone dialing sounds made of pairs of tones, as shown here: 1209 Hz 1336 Hz 1477 Hz 697 Hz 1 2 3 770 Hz 4 5 6 852 Hz 7 8 9 941 Hz * 0 # busy signal made up of a 480 hertz and a 620 hertz tone, with a cycle of 1/2 second on and 1/2 second Telephone Bandwidth below 400 hertz and above 3,400 hertz are eliminated. telephone network starts in your house. pair of wires runs from box at road to box ("entrance bridge") at your house. pair of wires usually using red and green wires second pair is usually yellow and black inside house. -------------------------------------------------------------------------------------- DTMF Dual Tone Multiplexed Frequency, tones heard while pressingkeys on telephone. Each key is a mixture of two {1} = 1209 Hz and 697 Hz mixed together: 1209Hz 1336Hz 1477Hz 1633Hz ABC DEF 1 2 3 A 697 Hz GHI JKL MNO 4 5 6 B 770 Hz PRS TUV WXY 7 8 9 C 852 Hz oper * 0 # D 941 Hz need 12K-15K volts AC (50/60) Hz at say 20-30 mA. neon sign (luminous tube) transformer usual source phone line rings there's 90 V RMS AC at 20 HZ on the line Phone In-Use Light >>---------+------+---->> phone line | | | o | / | / momentary switch | | | / | \ 1200 Ohm | / -----____| / \ /___\ SCR | / \ 600 Ohm / | ^^ ----- // / \ // /___\ LED | | >>---------+--------->> phone line Phone to audio interface (SSI202 input) .22 uf 10k pot 400v ||(----> Phone line tip o---)(--)||( <---o to SSI202 input )||( > Phone line ring o-------)||(----o---o ground Phone Off-Hook Indicator Phone Information voltage across the telephone line shows (typical numbers): On Hook: 40 to 50 VDC Off Hook: 4 to 6 VDC Ringing: 100 VAC standard" impedence of a telephone off-hook, is 680 ohms. Hanging a 680 ohm resistor across the telephone line will drop the voltage from 48V to about 5V, causing the line to go "active". This is how HOLD switches work. phone rang' indicator light This, will detect the ring signal, energize the relay which latches up, and the LED comes on and stays on till you push SW. ____ tip o--CC---RR----o---D<-o---o-->D----^ ^----o-----+ | | | SW | | | | | | | \-/ |- R|| B- LED Z C L||......... A | | |+ Y|| __.__ T+ R | | | +--o o---+ | | | | | | ring o------------o------o---o-----o------------+ CC=.47 uF 200 V. capacitor RR= 3k (depends on relay) D = 200V diode ( > < direction od diodes) Z = 12 zener RLY= any small relay SW= normally closed switch K = relay's contacts BAT= 9 V. battery R = 500 ohm (for LED) C = some (10) uF capacitor Get 3v relay... Set it up as follows: Audio Isolation Transformer To <--)||(---------------------+ )||( | <= Relay Contacts Speaker <--)||(---+ +--------o/ o 600ohm | | mmmmm DC 3v Relay Coil | | | | RED -----------|----+-------+ +-> | GREEN -----------+---------------------> To Dispatcher's Phone | | -+- indicates a connection, --- is not connected. | | DC current through phone and it transmits and receives audio. two phones and a current source (about 25mA) all in series give you a talking circuit. To ring bell you need 90V (RMS) 20Hz AC into phone (nominally) down to about 40V)different frequencies won't. can't ring the phone at 60Hz. This is what I have come up with: + | | - +---+------ - --+-||||---/\/\-+-- - ---+-------+ | | | | | R | | | | | | 24V | | | | --- | | --- | | | | +-||----------+ | | | | --- Sonalert C Sonalert ---| | C | | C | +-||-+ +--||---+ | _|_, _|_ | | / \ 15V 15V \ / | PHON -+- Zener Zener `-+- PHONE | | | | | | | | +----+---------- - - - ----------------+-------+ set R to give you a talking current (both phones offhook) 25mA. capacitors C about 0.47uF. phones are onhook present an open circuit When both phones are offhook very low resistance Telephone Power? Any substantial power drain from their lines WILL be detected. If it's large, the phone switch will conclude that you've dropped the phone in the bathtub or something like that, and will disconnect your line will check periodically to see if be reconnected). If it's small, switch report it to service people as a possible line problem, to be investigated before it causes a complete failure... and if they investigate and find that you're to blame, they will probably send you a bill for time current you can draw without eventually having it noticed is very small. Hold function for Telephone +-------+------+ R1 = 2.2K | | | R2 = 1 K -| SW R | R3 = 47 ohms | 1 | SCR = 2N5064, TIC47, or MCR104 | | | R LED | Well, that's it, just remember that 2 | | the cathode of both the SCR and the | | +----RING (Red) LED are towards bottom. +------SCR | | +----- TIP (Green) R | | 3 | | | | | +-------+------+ caller ID transmitted as 1200 baud tones Mark/1 is one cycle of 1200 Hz, Space/0 is nearly two cycles of 2200Hz, 8 bits ,asynchronous, one stop bit. data transmitted 30 bytes of 0x55 as a "channel seizure" signal (when demodulated, looks like 1/4 sec 600Hz square wave) 150 milliseconds of all marks; message-type word (one byte, value 0x04 indicates caller ID); message length word (one byte, num digits in calling number not include itself or the checksum); _ASCII_ digits of the phone number, least significant first; finally, a checksum byte, consisting of two's-complement of 8-bit sum of message-type word, message-length word, and data. DTMF FAQ Telephone Tone Dialing 0.1 By: T.H. Tsim (tsjoit@htsa.aha.nl) DTMF Dual Tone Multiplexed Frequency, Each key produces mixture of two frequencies 1209 Hz 1336 Hz 1477 Hz 1633 Hz ABC DEF 697 Hz 1 2 3 A GHI JKL MNO 770 Hz 4 5 6 B PRS TUV WXY 852 Hz 7 8 9 C oper 941 Hz * 0 # D (C&T) group Computing and Telecommunications network accessible bidirectional modem anyone in continental U.S. you want dial into any machine at NSC, from your terminal or PC dial the following sequence: atdt8002531731ww17011 your six digit telephone authorization access code same NSSC or NSFM or someplace in between. 'w' characters tell modem to wait until it hears next dial tone before dialing next group of digits. If you have call-waiting phone feature, insert string '*70w' after 'atdt' and before the '800' to temporarily disable feature for your dial in session. After you dial, modems will connect will get CONNECT message you are on line at specified speed. Just hit return key a few times until you get a prompt from the modem server to login. Login to modem server (your userid with no password) then connect to system you wish to use. server is a Xyplex server which speaks both IP and LAT can get to both IP and DECnet nodes If dailing into a Unix-based system, will want to put something along these lines in your '.login' file before you execute any 'tset ...' or 'eval `tset ...`' commands: if ($TERM == "network") then unsetenv TERMCAP setenv TERM vt100 endif Substitute type of terminal you are actually using for 'vt100' if you have some other physical or logical terminal type. When finished logout of the system you are using. will then put you back at the server prompt. If you are on a system on the network and you want to dial out somewhere, just type 'telnet scxy1'. will automatically connect you to a modem on server. Dial 'ath' to get the modem's attention. Then, at that point, can use Hayes dialing commands to dial outto another system as follows: Local call: ath atdt9wNNNNNNN Long distance: ath atdt7ww9,NNNNNNNNNN same dialing sequences you use for normal outgoing phone calls from NSSC phone system. When finished and modems hang up, line will close and reset itself. Xyplex terminal server currently has 32 ports, 16 being used for this modem server. The modems all Telebit TrailBlazer T2500s which are V.32 compatible (capable of running at 19.2kbaud). All 16 lines are configured for dial in (8 data bits, no parity, 1 stop bit) and 8 are configured for dial out. Telephone in use light +----+-------------+-------+-------- +9VDC | | | | | | |\ R5 R6 | +-------|-\ | | | | | >--+ LED1 | | +--|+/ | v ^ | | |/ | | CR2 R4 | | C+ | | | |\ | | / <+>--R1--+--R3--+----+--> | <--+--|-\ | |/ | | | | | >--+-B-| phone | | | +-------|+/ |\ line | | ^ | |/ | \ R2 C1 CR1 CR3 E+ | | | v U1 Q1 | | | | | | <->------+------+----+----+---------------------+-------- GND R1,R2 1 Meg R3 10 K R4 1 K R5 4.7 K R6 470 ohm C1 .005 uF CR1-3 1N914 diode LED1 any old led Q1 2N2222 or 2N3904 U1 LM339 quad comparator (be sure to connect power and ground) --> <-- are connected (jump) ^ or v cathode of diode + connection 9VDC any old 9VDC wall transformer works nicely a free line sits at more like 48 volts, a dead line (definitely not in use!) sits at 0. Detect phone RING When a phone line rings, there's 90 V RMS AC at 20 HZ on line. It's enough to give you a jolt you won't soon forget. Detector Schematic +-------------------------- + DC power supply | ^ CR2 | O---C1--+--R3---+--CR3>-+-------+-------+-----> ring det logic | | | | phone R2 ^ C2 R1 line | CR1 | | | | | | O---------------+-------+-------+-------+----- GND C1 .1 uf CR1,CR2,CR3 1N914 C2 10 uF R1 100K R2 10K R3 100K a ring indicator light that stays on until the phone acutally stops ringing: O---C1--+--R1---+--CR2>-+-------+--R2---+ | | | phone ^ C2 LED1 line CR1 | v | | | O-----------------------+-------+-------+ C1 1 uF, decent voltage C2 see text R1 10 K CR2 1N914 CR1 zener -- 9v or higher R2 1 K LED1 any old LED >>-----------------+------+---->> phone line | | | o | / | / momentary switch | | | / | \ 1200 Ohm | / -----____| / \ /___\ SCR | / \ 600 Ohm / | ^^ ----- // / \ // /___\ LED | | >>-----------------+--------->> phone line isolate phone line .22 uf 10k pot 400v ||(-----------> Phone line tip o-----)(----)||( <---o to SSI202 input )||( > Phone line ring o-----------)||(-----------o---o ground The transformer is a 600-ohm to 600-ohm line transformer. Phone Off-Hook Indicator On Hook: 40 to 50 VDC Off Hook: 4 to 6 VDC Ringing: 100 VAC The "standard" impedence of a telephone, when off-hook, is 680 ohms. Hanging 680 ohm resistor across telephone line drop voltage from 48V to about 5V, causing line to go "active". This is how HOLD switches work. This probably means that it is bad to load down phone line when phone is off hook. I wouldn't want to hang less than a 100Kohm load across it. Should probably measure this, and see how it affects the on-hook voltage. +9V | Phone+ -----+ |+ | LED R 2.7Mohm |- | | | R 680 ohms | 5 |\ 4 3 |\ 2 | +-----------| >o------+-----| >o---------------+ | |/ 4049 | |/ 4049 | | | | | | | R 0.56Mohm | 14 |\ 15 | | +-----| >o---------------+ Phone- ------+ |/ 4049 | | GND R = resistor. Those other things are inverters. Connect 9V battery across +9V and GND, above. Tie all unused inputs (pins 7,9,11) of the 4049 to GND! Don't let 'em float. Tie Vcc (Pin 1) of 4049 to +9V Tie GND (Pin 8) of 4049 to GND Voltage going into pin 4 of 4049 is: Phone voltage Voltage at pin 4 6V 1V 48V 8V 100V 16V 'phone rang' indicator light energize relay which latches up, LED comes on stays on till you push SW. ____ tip o--CC---RR----o-----D<---o-----o------>D----^ ^----o-----+ | | | SW | | | | | | | \-/ |- R|| B- LED Z C L|| ............ A | | |+ Y|| __.__ T+ R | | | +--o o---+ | | | | | | ring o------------o----------o-----o---------o----------------+ CC=.47 uF 200 V. capacitor RR= 3k (depends on relay) D = 200V diode ( > < direction od diodes) Z = 12 zener RLY= any small relay SW= normally closed switch K = relay's contacts BAT= 9 V. battery R = 500 ohm (for LED) C = some (10) uF capacitor Phone Line to Audio used an audio coupling transformer and a capacitor. The primary windings add in series to 500 ohms. Instead of connecting them directly together I added a cap between them. I think it was somthing like 0.047 micro farads with a 600vlt rating. And the secondary which is 500 ohms runs into the control room mixer. Tip >------------/ II / II /------------< (primary winding 1) / II / / II / >-----X------/ II / I II / 0.047 uF = II / -----------CT (secondary winding) I II / >------X------/ II / Output Side / II / to Mixer (primary winding 2) / II / / II /-------------< Ring >-------------/ II Try this circuit it works great for us in the studio. Just make sure you use properly rated components. Use old phones as an intercom To ring the bell you need to put 90V (RMS) 20Hz AC into the phone (nominally). Lower voltages will work (down to about 40V) but different frequencies won't. You can't ring the phone at 60Hz. ringing circuit in a PBX I built but it consists of a 20Hz sinewave generator, a push-pull power booster and a big transformer. Much too elaborate for a simple 2-phone intercom circuit, and anyway the ringing voltage could painfully zap a kid. + | | - +-------+------ - - --+---||||---/\/\/--+---- - -----+-------+ | | | | | R | | | | | | 24V | | | | --- | | --- | | | | +---||------------+ | | | | --- Sonalert C Sonalert --- | | C | | C | +---||--+ +--||---+ | _|_, _|_ | | / \ 15V 15V \ / | PHONE -+- Zener Zener `-+- PHONE | | | | | | | | +-------+------------------ - - - -------------------+-------+ As before, set R to give you talking current (both phones offhook) of about 25mA. Start with 1K ohm. Leave it in if the phones work well enough; the current is not very critical. The capacitors C are audio bypass capacitors and should be about 0.47uF. When the phones are onhook they present an open circuit, and the 24V battery voltage is not enough to overcome the 30V series drop of the Zeners and no current flows. When both phones are offhook they present a very low resistance and the talking current (determined by R) flows. only one phone is offhook it places its low DC resistance across Zener diode on its side so that the full 24V supply is applied to the other side. overcomes the voltage drop of other Zener diode so the other Sonalert beeps. The wonderful thing about Sonalerts is that they make a loud noise with only a few milliamps of current so the series resistor R doesn't matter. Especially nice is a pulsing Sonalert which goes "Beep beep beep" automatically. While the far-end Sonalert is beeping, you hear the beeping in the near-end receiver (at low volume thanks to the bypass capacitor across the far-end Sonalert) to confirm that the line is working and the other end is being signaled. The power supply can be three 9V batteries in series but since 80% of power is lost in series R rather than in powering phones it seems a little wasteful. A 24V wall wart with clean filtering would be better. The signaling components can be mounted inside the phones. Only two wires are needed to go to each phone, and the power supply can be mounted centrally, out of harm's way. If R is adequately big (1/2 watt) and has enough ventilation then both lines can be indefinitely shorted out without any fire hazard and there is not enough voltage anywhere to hurt anyone. I have tested this with 500-type phones and two different types of piezo buzzers (pulsing sonalerts and non-pulsing brand X ones) and it works great. Telephone Power? They aren't in the business of supplying power, and they ARE in the business of finding faults in their lines. Any substantial power drain from their lines WILL be detected. If it's large, will disconnect your line (will check periodically to see if drain has gone away reconnected). ======================PHONE_CALLER_ID==================================== Caller ID Calling Number Delivery (CND), allows the called Customer Premises Equipment (CPE) to receive calling directory number and date time during first 4 second silent interval in ringing cycle. customer must contact Bellcore Client Company to initiate CND service. data signalling interface has the following characteristics: Link Type: 2-wire, simplex Transmission Scheme: Analog, phase-coherent FSK Logical 1 (mark) 1200 +/- 12 Hz Logical 0 (space) 2200 +/- 22 Hz Transmission Rate: 1200 bps Transmission Level: 13.5 +/- dBm into 900 ohm load believe transmission level -13.5 dBm.) PROTOCOL 8-bit data words (bytes), each bounded by a start bit and a stop bit. The CND message uses the Single Data Message format . Channel Carrier Message Message Data Checksum Seizure Signal Type Length Word(s) Word Signal Word Word CHANNEL SEIZURE SIGNAL channel seizure is 30 continuous bytes of 55h (01010101) providing a detectable alternating function to the CPE (i.e. the modem data pump). CARRIER SIGNAL consists of 130 +/- 25 mS of mark(1200 Hz) to condition the receiver for data. MESSAGE TYPE WORD indicates the service and capability associated with the data message. message type word for CND is 04h (00000100). MESSAGE LENGTH WORD specifies total number of data words to follow. DATA WORDS are encoded in ASCII first two words represent month next two words represent day of the month next two words represent hour in local military time next two words represent minute after hour calling party's directory number represented by remaining words in data word field If calling party's directory number is not available the data word field contains an ASCII "O". If invokes privacy , data an ASCII "P". CHECKSUM WORD contains the twos complement of the modulo 256 sum of other words in the data message (i.e., message type, message length, and data words). receiving equipment may calculate modulo 256 sum of the received words and add this sum to the reveived checksum word. result of zero generally indicates correctly received. EXAMPLE CND SINGLE DATA MESSAGE beginning with the message type word, follows: 04 12 30 39 33 30 31 32 32 34 36 30 39 35 35 35 31 32 31 32 51 04h= Calling number delivery information code (message type word) 12h= 18 decimal; Number of data words (date,time, and directory number words) ASCII 30,39= 09; September ASCII 33,30= 30; 30th day ASCII 31,32= 12; 12:00 PM ASCII 32,34= 24; 24 minutes (i.e., 12:24 PM) ASCII 36,30,39,35,35,35,31,32,31,32= (609) 555-1212; calling` party's directory number 51h= Checksum Word DATA ACCESS ARRANGEMENT (DAA) REQUIREMENTS To receive CND information, the modem monitors phone line between first and second ring bursts without causing DAA go off hook in conventional sense, which would inhibit transmission of CND by the local central office. simple modification to existing DAA circuit easily accomplishes task. (I will mail the Rockwell data sheet, which includes the suggested schematic diagram.) MODEM REQUIREMENTS data signalling interface parameters match those of a Bell 202 modem, the receiving CPE need not be a Bell 202 modem. V.23 1200 bps modem receiver used to demodulate the Bell 202 signal. ring indicate bit (RI) used on a modem to indicate when to monitor the phone line for CND information. After RI bit sets, indicating first ring burst, the host waits for the RI bit to reset. host then configures the modem to monitor the phone line for CND information. (I'm skipping some Rockwell-specific information here.) CND signalling starts as early as 300 mS afte first ring burst and ends 475 mS before the second ring burst APPLICATIONS Modem manufacturers soon implementing new modem features based on CND information as this service becomes widely available. Once CND information is received the user may process the information in a number of ways. The date, time, calling party's directory number can be displayed. Using a look-up table, calling party's directory number can be correlated with his or her name and the name displayed. CND information used in additional ways such as a. Bulletin board applications b. Black-listing applications c. Keeping logs of system user calls, or d. Implementing a telemarketing data base ANI Automatic Number Identification is a mechanism telephone companies determine account charged for call originally for billing purposes and predated SS7 (Signaling System 7) and (C)LASS (Local Area Signaling Services "C" added by Bellcore after divesture) services which make CNID or Calling Number IDentification as Caller-ID is more properly known, More recently, ANI used to report 800 and 900 subscribers, ANI is similar to CALLER-ID and may provide the same information, they are actually two different services Caller-ID a Telco offering that is a byproduct of (C)LASS Currently there are two types of Caller-ID. "basic" service) just returns the calling number or an error message and the date/time of the call. ("enhanced" Caller-ID) also may return the directory information about the calling number. Caller-ID information provided 1200 baud, 7 data bits, 1 stop bit data stream usually transmitted following the first and before the second ring signal on the line. not a standard Bell 212 or CCITT v22 data format so a standard modem will probably not receive it. Further, the serial information exists only from recipient's switch to callee's location. Between carriers the signal exists as data packets. The signal is provided before the circuit is complete: picking up receiver before data stream finished will stop/corrupt the transmission. "short form" containsdate/time and calling number "long form" also name and possibly address (directory information) of the calling phone. "short form" stream consists of set null values, followed by two byte prefix, followed by (Month/Day), TIME (24 hour format)number , area code in ASCII, followed by a 2s compliment checksum. Most modems/caller id devices will format data but raw stream like this : 0412303232383134333434303735353537373737xx or (prefix)02281334407555777(checksum) formatted output would look like this: Date - Feb 28 Time - 1:34 pm Number - (407)555-7777 Caller-ID s be forged/altered the signal is provided by the local Telco switch and the calling party's line is not connected until after the phone is answered, generally signal cannot be altered from distant end. Manipulation would have to take place either at switch or on the called party's line. Presto Chango" can transmit an extra ADSI modem tone after the call has been picked up that will cause a susceptible box to display the later information. "ID Blocking" Generally this is done by pressing star-six-seven before making the call. blocking is provided by a "privacy" bit that is transmitted along with the CNID information so is still available to the Telco switch, just not to the subscriber as a CNID signal "Out of Area" call came from outside the Telco's service area no available information or has chosen not to return what information it has. Blocked" or "Private" either permanent call blocking enabled or has dialed star-six-seven for this call. You do not have to answer either. No Data Sent" Signal was received consisting entirely of nulls or with missing information but a proper checksum. Caller ID info? Phone gets first ring, duration 2 seconds Delay 0.5 seconds after first ring Send 30 bytes of '01010101', duration 250ms (channel seizure signal) Send 150ms of marks (carrier signal) Send an 8 bit "parameter word type" 00000100 = Caller ID 00001010 = message waiting indicator 10000001 = Test for caller ID Send 8 bit number representing number WORDS in message two digits month two digits day of the month w/leading zero for 1 to 9. two digits hour in local military time. two digits are the minutes in local time. remaining digits (message length -8) are the telephone number of calling party. last field may = 'P' or 'O' for blocked or out-of-area last 8 bits the checksum. the two's complement of modulo 256 sum of the other words in the data message. This sum does not include the channel seizure signal or the carrier signal. Total transmission duration = 718ms data signalling interface has the following characteristics: Link Type: 2-wire, simplex Transmission Scheme: Analog, phase-coherent FSK Logical 1 (mark) 1200 +/- 12 Hz Logical 0 (space) 2200 +/- 22 Hz Transmission Rate: 1200 bps Transmission Level: 13.5 +/- dBm into 900 ohm I believe the transmission level is meant to be -13.5 dBm. PROTOCOL uses 8-bit data words (bytes), each bounded by a start bit and a stop bit. The CND message uses the Single Data Message format shown below. Channel Carrier Message Message Data Checksum Seizure Signal Type Length Word(s) Word Signal Word Word CHANNEL SEIZURE SIGNAL channel seizure is 30 continuous bytes of 55h (01010101) providing a detectable alternating function to the CPE (i.e. the modem data pump). CARRIER SIGNAL consists of 130 +/- 25 mS of mark (1200 Hz) to condition the receiver for data. MESSAGE TYPE WORD indicates the service and capability associated with the data message. The message type word for CND is 04h (00000100). MESSAGE LENGTH WORD specifies the total number of data words to follow. DATA WORDS are encoded in ASCII and the following information: o first two words represent the month o next two words represent day of the month o next two words represent hour in local military time o next two words represent minute after the hour o calling party's directory number is represented by remaining words in data word field If calling party's directory number is not available to the terminating central office, the data word field contains an ASCII "O". If calling party invokes the privacy capability, the data word field contains an ASCII "P". CHECKSUM WORD contains the twos complement of the modulo 256 sum of the other words in the data message (i.e., message type, message length, and data words). The receiving equipment may calculate modulo 256 sum of the received words and add this sum to the reveived checksum word. A result of zero generally indicates that the message was correctly received. Message retransmission is not supported. EXAMPLE CND SINGLE DATA MESSAGE example of a received CND message, beginning with the message type word, follows: 04 12 30 39 33 30 31 32 32 34 36 30 39 35 35 35 31 32 31 32 51 04h Calling number delivery information code (message type word) 12h 18 decimal; Number of data words (date,time, and directory number words) ASCII 30,39= 09; September ASCII 33,30= 30; 30th day ASCII 31,32= 12; 12:00 PM ASCII 32,34= 24; 24 minutes (i.e., 12:24 PM) ASCII 36,30,39,35,35,35,31,32,31,32 = (609) 555-1212; calling party's directory number 51h = Checksum Word DATA ACCESS ARRANGEMENT (DAA) REQUIREMENTS To receive CND information, modem monitors the phone line between first and second ring bursts without causing the DAA to go off hook in the conventional sense, which would inhibit the transmission of CND by the local central office. A simple modification to an existing DAA circuit easily accomplishes the task. MODEM REQUIREMENTS the data signalling interface parameters match those of a Bell 202 modem, the receiving CPE need not be a Bell 202 modem. A V.23 1200 bps modem receiver may be used to demodulate the Bell 202 signal. The ring indicate bit (RI) may be used on a modem to indicate when to monitor the phone line for CND information. After the RI bit sets, indicating the first ring burst, the host waits for the RI bit to reset. The host then configures the modem to monitor the phone line for CND information. Bellcore specifications, CND signalling starts as early as 300 mS after the first ring burst and ends at least 475 mS before the second ring burst Once CND information is received The date, time, and calling party's directory number can be displayed. a. Bulletin board applications b. Black-listing applications c. Keeping logs of system user calls, or d. Implementing a telemarketing data base CALLER ID MESSAGE FORMAT Message Description Power Ring first ring power ring get attention Caller-ID receiver. The ring Is followed by 500 ms of silence. Channel Seizure Sync bytes, consisting of 30 ASCII U�s (250 ms duration). Mark Signal l2OO-Hz marking tone, 150 ms duration, Message Message(or parameter)type,length, message bytes,checksum. Post-Msg Mark After message data, an 80 ms mark tone sent (optional). Post-Msg Silence All tones must end at least 475 ms before the next ring. Giovanni 1. About this FAQ Caller Line Identification, CLI, Caller ID, Caller Display. All are different names for the service provided by many telephone companies that allows one to see the number of the person who is ringing you. This FAQ aims to help anyone who wants to use Caller ID, in particular those who want to pass this information to their computer. Inevitably, I concentrate on what I know best - the UK phone system and Caller ID under Windows, but I also cover other countries and operating systems; the principles are much the same. This revision updates the UK modem situation, and should fix most of the bad links that have crept in over the last year or so. This FAQ is available from http://www.ainslie.org.uk/callerid.htm and is Copyright 1998-2001 Alastair Ainslie, with due acknowledgement of any trademarks. Thanks to all in uk.telecom who have posted anything useful that I've nicked. I don't pretend to be an expert on this, but I've learnt a lot from posts on uk.telecom in the last year or so in the course of my research for my own system, and thought I might as well put it together for other people - it seems to be a pretty popular subject on the group. I've put a lot of these posts together in a ZIP file. 2. Caller ID jargon CLI Caller Line Identity, data sent from the exchange that identifies the calling party's number. This isn't much good without... CLID Caller Line Identity Display or CLIP Caller Line Identity Presentation or CND Caller Number Display, but in practice most people just refer to CLI, Caller ID or Caller Display which is what BT calls its version of the service. I will try to use the non-technical term Caller ID. Caller Return a.k.a. 1471. Tells you the last number to call and gives you the option to return the call if the number is known. Completely independent of Caller ID. CNAM Caller Name Display - see below. CWID Call Waiting ID, shows the number of a waiting caller while you are already on the phone. See below Presentation Number allows the caller to send a number other than the one belonging to the line they are using. The presented number must belong to the caller; a typical use would be sending the main switchboard number from a direct line extension. BT don't offer PNs yet but are working on it. ANI Automatic Number Identification, a "super" Caller ID that is used by the emergency services, freephone providers, and by telcos for billing purposes. It cannot be blocked, but is not usually made available to consumers except by accident. Seems to be more of an American term, but BT have something similar. ACR Anonymous Call Rejection, the automatic rejection of calls made by people who withhold their number, who are often telemarketers - see below DNIS Dialled Number Information Service, tells the called party which number was dialled by the caller. Typically used by call centres with different numbers for different services. Oftel The Office of Telecommunications, a non-ministerial government department set up under the 1984 Telecommunications Act to regulate the telecoms industry in the UK. They publish a CLI Code of Practice for Network Operators (http://www.oftel.gov.uk/tech/cli698.htm) and a version of this for consumers (http://www.oftel.gov.uk/tech/clic698.htm). Both are pretty turgid but useful to wave at phone companies who are giving you the run-around. A good glossary of telecom abbreviations can be found at http://www.eurovoice.co.uk/glossary.htm and http://testmark.com/callerid.html has a good history of Caller ID. Caller ID In days of analogue exchanges, ANI Automatic Number Identification (ANI) developed for call billing purposes. privileged connections such as the 999/112/911 service, police, and, later on, freephone providers. continue to use ANI which is completely separate from Caller ID and cannot be blocked. fake number that I send? Caller ID signal generated at called party's exchange caller's line connected after called party has answered should be impossible to fake Caller ID data without access to the called party's line or exchange. Certain older Bellcore Caller ID boxes contain chips (such as the Motorola M145447) that can be tricked into receiving extra Caller ID tones during a call. I guess this is the loophole exploited by the $300 box advertised here (#107) or the "Presto Chango" box. The other case where extra Caller ID tones can be sent during a call is Call Waiting ID, and this is inherently far more vulnerable to hacking, a fact exploited by the 'orange box'. But unless your victim happens to have the right sort of box, there is no way of faking your number from your own line. Without an SS7 connection, you don't have a hope. In any case, if you do anything too naughty, the authorities will still be able to track you down using the billing data. All you can do is make the data unavailable. Examples of this are using 141/*67 or placing a call via the operator, a non-SS7 calling card, a payphone, or an analogue mobile phone. 3.1 users : When the Connection Description dialogue box appears, type something to fill the Connection Name box, then press OK. Next type something to satisfy the need for a Phone Number. Now you have two options, TAPI mode or COM port mode. It's best to start off with the more sophisticated TAPI mode, then give COM port mode a try if TAPI doesn't work - Win3.1 users only get COM port mode. If you are using TAPI, choose your modem from the 'Connect Using' drop-down list. The Connect dialogue will appear - press Cancel. Then type AT#CID=1 and press Enter to enable Caller ID in formatted mode. For some reason, Hayes Optimas use AT%CCID=1 and I've seen AT+VCID=1 (recent Cirrus etc), AT#CC1 (older Cirrus, VoiceSurfr) & AT*ID1 suggested for other modems; IBM has a good page of modem strings. Sometimes you may need to switch to Voice mode with AT#CLS=8 or similar. If you want to poke around with your modem settings, look in the .inf file or in the Registry under HKEY_LOCAL_MACHINE\System\ CurrentControlSet\Services\Class\Modem (I take no responsibility for any fiddling with the Registry whatsoever, if you don't know what you're doing, don't do it!!) Don't forget that the modem sends the data after the first ring, regardless of when it arrives at the modem, so don't let it answer on the first ring!! (i.e. no S0=1) Then ring the number from another line, or use 17070. following fields should appear : NAME= NMBR=01234-567890 DATE= TIME= NAME will be blank or "WITHHELD" unless your telco supports Caller Name Display, which is unlikely in the UK (see above). The procedure is the same for COM port mode, but you select your modem's COM port from the list, and it's best to go for AT#CID=2, Caller ID in Unformatted mode. AT#CID=0 switches off Caller ID. AT#CID? gives the Caller ID status of the device (0=off i.e. something's not working, 1=on) but some devices fake this for compatibility purposes.