User`s guide

7-7
When the call has finished and was successful, both LEDs will light for a minimum of
three seconds. If the unit has been configured to originate calls only then both LEDs will
be turned off. If the unit has been configured to answer incoming calls or respond to
SMS messages, the LEDs will remain lit until the next call.
If the call is unsuccessful due to an error or a network problem, an error code will be
displayed twice to describe the nature of the failure. If the unit has been configured to
originate calls only then both LEDs will be turned off. If the unit has been configured to
answer incoming calls or respond to SMS messages, the unit will return to a flashing
green LED to indicate the status of the radio and signal strength, as described in Table
7-2.
7.7 Behavior in GPRS Mode
GPRS mode is automatically selected when the unit is configured to connect to an IP
address and is allowed to originate calls. There are several stages to making an Internet
connection to the destination server. The red LED indicates the progress of this
connection process, as shown in Table 7-4.
When the call has finished and was successful, both LEDs will light for a minimum of
three seconds. If the unit has been configured to originate calls only then both LEDs will
be turned off. If the unit has been configured to answer incoming calls, respond to SMS
messages or maintain an Internet connection, the LEDs will remain lit until the next call.
If the call is unsuccessful due to an error or a network problem, an error code will be
displayed twice to describe the nature of the failure. If the unit has been configured to
originate calls only then both LEDs will be turned off. If the unit has been configured to
answer incoming calls, respond to SMS messages or maintain an Internet connection,
the unit will return to a flashing green LED to indicate the status of the radio and signal
strength, as described in Table 7-2.
When the DCM-200 originates an Internet connection, it must request access to the
cellular provider’s GPRS service, then access to the Internet and finally access to the
destination server. All of this negotiation takes a certain amount of time. To reduce this
time the DCM-200 can maintain access to the Internet at all times and only needs to
request access to the destination server, which only takes a few seconds. This is often
referred to as an “always on” connection. This feature is enabled by checking the
“Maintain Internet Connection” box in MP32 (see Chapter-5). If this feature is used it is
not possible to answer incoming phone calls or respond to SMS messages.
7.8 Paging via Voice Call
In CSD mode, some cellular service providers allow a mobile device to originate a data
call (“mobile-originate”) or to receive one (“mobile-terminate"). To receive a data call the
cellular account is usually assigned a “data” phone number. However, some providers
do not support mobile-terminate connections.