A good data connection really needs to be made on the DB-25 interface in order for the remote serial interface to work. In the uncommon case one needs to upgrade firmware, it is a simple process provided:
You are using a windows computer with a serial port
You use a straight-through serial cable with a female 9-pin gender bender
You unplug the data connector (25 pin) when doing the update or it may not work.
Performing a flash upgrade erases the non-volatile RAM, which is where the
modem’s configuration is stored. Users shall re-enter the desired configuration
parameters.
The upgrade is performed without opening the unit, by connecting the modem to the serial port of a computer and executing a flash uploader utility program. The cable to connect the PC to the modem is the same as is used for normal EIA-232 remote control, and comprises three wires connected between two 9-pin ‘D’ type female connectors. Ensure this cable is connected and working properly before proceeding with a
flash update.
