I have a home alarm system with RS-485 network, currently E-mail via 
dialup modem is available, would like to add capability of dial out with 
voice messages:

1: Would be a dozen or so possible brief, less than 20, or even a dozen 
words each messages. Messages would be stored digital (text file) and 
synthesized for output.

2: Message to be sent would be directed by a PLC as a message number. 
Modbus protocol is available on the RS-485, along with custom I/O on the 
network.

3: PLC would also have a list of phone numbers to use.

4: Person receiving message would respond with dial tone or 2 key press. 
Depending on response (I will handle alarm, or dial next number on list, 
etc.) PLC would initiate call to next on phone list, or stop since 
someone has acknowledged they will handle situation.

5: Yes, a lot of cell phones have E-mail capability, and the recipients 
usually have E-mail, but quick response might be called for, and a land 
line would be first choice. 911 as a receiver could be likely.

This is in very early planning stages, looking for ideas of equipment, 
components, schemes. I have ability to build up and program PIC boards 
with digital I/O, some analog output, probably could handle analog out 
somewhat. Haven't done anything with audio. Not adverse to a couple of 
$100 in cost.

Thanking ahead for thoughts. :)
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