excerpts from a Motorola MC145447 spec sheet

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 an 8 bit number representing the number of WORDS in the message

Now, the actual data:

The first two digits are the month with a leading zero for JAN to SEPt.
The next two digits are the day of the month w/leading zero for 1 to 9.
The next two digits are the hour in local military time
. The next two digits are the minutes in local time.
The remaining digits (message length -8) are the telephone number of the calling party. The last field may include the 'P' or 'O for blocked or out-of-area calls.

The last 8 bits of the message are the checksum. The check sum is the two's complement of the 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

The above description is as stated in the Motorola MC145447 Caller ID Receiver data sheet, and in the Cermetek Application Note AN-107. I have not yet seen the actual data but will have my CID > RS232 circuit complete this weekend. I will then be able to shead a little more light on the topic.

from a post to comp.dcom.telecom by schuch@phx.mcd.mot.com (John Schuch)

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