| ??? 04/07/09 01:47 Modified: 04/07/09 01:50 Read: times |
#164419 - Caller ID Responding to: ???'s previous message |
There are two popular caller ID types.
US and Aust and most popular for other countries as well ========================================================= 1200baud (8N1), BEL202 modem tones (most popular, Uses the Bellcore GR-30 Standard) ***** Some modems have this hardware inside ******** DTMF Caller ID =============== using DTMF tones (mainly through some European countries and some UK) You need to a) "sniff" the phone lines with a high impedance (ie do not load the line) and b) DC block with a 250 capacitor (as the ring signals are quite high) c) to meet telecom safety, some form of isolation through a transformer may be needed The caller ID is typically send after the 1st ring, as the 1st ring "wakes up the caller ID device". |
| Topic | Author | Date |
| Modem CLID | 01/01/70 00:00 | |
| CLID? | 01/01/70 00:00 | |
| Caller ID ? CLI ? What is the difference ? | 01/01/70 00:00 | |
| None! | 01/01/70 00:00 | |
| CLI Standards vary | 01/01/70 00:00 | |
| BT specifications | 01/01/70 00:00 | |
| Thanks ! | 01/01/70 00:00 | |
Caller ID | 01/01/70 00:00 |