6 Configure the Operation Modes
Since there is no connection, data can not be sent in a stream. UDP uses packages. There are
several ways to define the content for a package.
UDP MaxPacketSize
is a limit for the size of UDP packets. When the amount of data received on the
serial port reaches this limit, the UDP Frame is assembled and sent to the destination.
UDP Timeout
defines when the NetCom
+
sends the received data as a UDP Frame. If the reception
of serial data is interrupted for this time (in milliseconds), the data sampled so far is
sent to the destination. A value of zero causes all data to be sent immediately, use
“
-1
” to disable the function of timeout trigger. A good value to start with is
30
, if no
specific parameters are given by the external devices. This is the default since fimrware
version 3.3.5
UDP Trigger
defines a sequence of characters. As soon as this sequence is detected in the received
data, all data up to the end of this Trigger is sent to the destination. In most situations
such a Trigger includes control or other special characters. Enter them numeric: as
\xHH where HH is the hexadecadic code of the character, or as \OOO where OOO is
the octal code of the character. The backslash itself must be doubled as \\.
If none of these options is used, the packets definition is not specified. This will result in unpre-
dictable separation of serial data, depending on internal hardware behaviour. Typically this is not
handled good by the application software.
6.2.2.2.7 IP-Modem
The serial port of a NetCom
+
may mimic (emulate) a serial modem. There
is the separate section
8
defining this functionality. Here are the basic network parameters only.
Mode
IP Modem
TCP Port(Data)
[2001 ]
Destination
[
]
IP Modem Config
[
]
Figure 82: IP-Modem
A serial modem accepts connections from a phone line, while an IP Modem accepts connections
from the network, in this case via TCP/IP. The TCP port for this is defined as the
TCP Port(Data)
,
similar to TCP Raw Server mode. This is the only parameter required to set here.
All other values are normally defined by AT-commands via the serial port. However for short,
Destination
allows for up to four predefined targets, available with special Dial commands. The
IP Modem Config
is known as the Init String in standard modems.
September 2016
NetCom Plus User Manual
84
