Zn=x - store telephone number, Syntax, Defined values – Comtrol AT Commands User Manual
Page 38: Result codes, 7 - plug and play serial number, Example

AT Commands for CX81801/CX06833/CX81300/CX06827 Modems Reference Manual
Conexant
102184B
3-12
&Zn=x - Store Telephone Number
The modem can store up to four telephone numbers and each telephone number dial
string can contain up to 31 digits. (Requires 256-byte NVRAM installed.)
Syntax
&Z
Defined Values
Decimal number from 0 to 3 corresponding to the selected
telephone number.
string
from 0 to 31 characters.
Result Codes
OK For
≤ 3, and
ERROR
If
installed or is not operational.
%7 - Plug and Play Serial Number
Sets and stores eight serial numbers in hex format used for serial Plug and Play and for
ISA Plug and Play which use the Conexant 11596 Plug and Play device. Applicable to
Desktop configuration only.
Syntax
%7<8 hex numbers>
Example
%7<8 hex numbers>
Result Codes
OK
<8 hex numbers>
ERROR Otherwise
To display the stored serial number, issue AT"?