B&B Electronics VFG3000 - Manual - Manual (Page 53)

A DVANCED C OMMUNICATIONS W ORKING WITH M ODEMS
R EVISION 1 P AGE 37
IP R
OUTING
The Ethernet icon in the Communications window contains a property called IP Routing. If
this facility is enabled, incoming packets from non-firewalled modem interfaces will be
compared against the IP address and netmask for the Ethernet interface, and will be
forwarded to that interface should a match occur. This facility is most often used with dial-in
connections, and allows IP access to all devices connected to the Ethernet port, provided a
suitable route is defined by the client.
C HECKING THE M ODEM S TATUS
In order to help debug modem connections, Fieldbus Gateway Manager provides the
GetInterfaceStatus function. This function takes a single argument, which is the numeric
index of the required interface. Interface zero is always the Gateway’s loopback interface.
Next comes the Ethernet interface, if it is enabled, such that the first PPP interface is
numbered 1 when Ethernet is disabled and 2 when it is enabled.
The function returns a string, which can be interpreted according to the following table…
S
TATUS
M
EANING
CLOSED The interface has not yet been initialized. This state will
only occur for a short time during system start-up.
INIT The modem is being initialized. If the connection
remains in this state, there are probably errors in the init
strings being sent to the modem.
IDLE The link is idle. GSM modems will return a number at
the end of the string to indicate signal strength. The next
table explains how to interpret these values.
SMS The modem is sending SMS messages, or polling the
modem to see if new SMS message are available. If SMS
messaging is enabled for a modem, you will see this state
appear for a short period every five seconds.
CONNECTING The modem is establishing a connection. This state
typically appears only for client connections, and
indicates that a call is being placed.
LISTENING The modem is waiting for a call. This state appears only
for server connections. Note that GSM modems will also
return an IDLE state while waiting for a call in order to
show signal strength.
ANSWER The modem is answering a call and trying to negotiate
the Baud rate for the connection. This state appears only
for server connections. If the connection is established,
the modem will enter the CONNECTED state.