Comtrol AT Command Set Rev A - Manual (Page 139)

AT Commands Reference Manual
100722B Conexant 3-113
3.4 Cellular Commands
Cellular direct connect, supported by portable application modems, allows a direct
interface to most cellular telephones eliminating the need for other intelligent interfaces.
Landline modems operate with the telephone system by either going off-hook detecting
dial tone and the dialing the telephone number using pulses or DTMF digits, or detecting
the RING signal and answering the call. Intelligent cellular phone interfaces connect
between the modems RJ-11 socket and the cellular phone's data interface. The interface
provides landline features to the modem (line current, dial tone, ringing, etc.), and
translates the modem's signals (off-hook, DTMF digits, etc.) into signals that the cellular
phone understands. Once connected the interface acts as a transparent link between the
modem and the cellular telephone.
The Direct Connect Modem interfaces directly to the cellular phone's data interface and
provides direct control over the cellular phones operation. For example if the user were to
instruct the modem to dial using the ATDTnnnn command the modem would relay the
telephone number and the SEND command to the cellular phone over the data interface.
The modem connects to the cellular phone using a special cable which must be purchased
separately. A different cable is required for each cellular phone or make of cellular
phones.
3.4.1 Cellular Phone Drivers
The data interface to cellular phones differs between manufacturers and models and
requires a unique cellular phone driver for each phone or group of phones. Therefore the
particular phone driver needs to be downloaded from the PC into the modem's RAM
before the modem can be used directly with the cellular phone. If a driver is not loaded
the modem will operate as a normal landline modem.
3.4.2 Cellular Commands
^C2 - Download Cellular Phone Driver
The ^C2 command initiates the cellular phone driver download function. Upon receipt of
the command, the modem issues the "OK" message. The user then performs an ASCII
download of the driver (in .S37 format) from the host to the modem, typically using a
communications software package (with transmit pacing turned off).
^C2 Download Cellular Phone command
Result Codes
OK
[Download Process]
OK
Cellular phone driver download completed successfully
ERROR Cellular phone driver download not completed successfully,
e.g., checksum of record (in S37 file) is not correct, driver size
is larger than 2k bytes, or an invalid driver is downloaded, or
modem is connected.