0: No Flow Control
1: Xon/Xoff
2: Hardware
7.12 When Do I Need A Null Modem Cable?
The Land-Cellular modem's RS-232 serial port is wired to act as the Data Communication
Equipment (DCE), while a typical home computer or laptop system is designated as the Data
Terminal Equipment (DTE.) As long as you are connecting two different devices (DCE-to-DTE),
you must use a straight-through serial cable. However, if you are connecting two like devices
(DTE-to-DTE or DCE-to-DCE), it is necessary to use a Null Modem Cable. Use the Null Modem
cable to attach the modem to PDAs and handheld computers. Desktop and notebook computers
require a straight through cable.
7.13 Why Do I Have To Set The Phone Number As #777?
The act of dialing #777 automatically triggers the Cellullar Network to connect the call as a
Packet Data TCP/IP call on the 1xRTT network. To enable automatic packet call connections use
the command:
AT$QCPKND=0
To disable this feature, issue:
AT$QCPKND=1
7.14 What Is Dormancy?
The CDMA packet data service supports a dormancy feature. When no data is being transferred
on the cellular link for a period of time, the RF traffic channel is released. However the PPP states
and the IP address are retained. To the end-user, the network connection will remain up, but the
packet data call timer will stop. The modem can initiate dormancy if it is configured with the
AT+CTA
command before origination of the packet call. Alternatively, the base station can also
initiate dormancy.
