Datasheet

INSYS ETHERNET 5.X Operating Modes
Nov-06 27
Important information regarding UDP connections
TCP protocols have a connection management, whereas for UDP protocols the data
packets are simply dispatched to the network. The UDP protocol does not confirm if the
data was actually received by the recipient. For UDP it may also occur that sent data
packets arrive at the recipient in a different order (due to routing). The user protocol rest-
ing on UDP would need to accept all these tasks.
Note
It is therefore recommended to favor TCP to UDP connections wherever
possible.
However, if a UDP connection is inevitable, note the following.
An empty UDP packet is sent during the outgoing UDP connection setup (ATD) to indi-
cate the connection request to the remote terminal.
For an incoming connection request, each UDP packet will cause the output of the mes-
sage RING, either until the connection is automatically accepted (ATS0=<n>) or until it is
manually accepted with ATA.
Note
For the connection of two INSYS Ethernet, both devices must be set to
ATU.
To terminate the UDP connections between two devices, the escape sequence
(<pause>+++<pause>) must be entered on both sides to switch the modules from data
to command mode.
As the escape characters are also transmitted to the recipient, it is possible for UDP con-
nections that the +++ sequence of module #2 will trigger RING at module #1 which is
already in command mode. If ATS0=1 is set at module #1, this will automatically result
in the connection acceptance being repeated.
The value for ATS0 should therefore be larger than 3. The optimum manual connection
acceptance is performed with ATS0=200 and ATA.
If larger amounts of data are sent via UDP and the receiving module does not manage to
output the data at the serial interface in time, this may result in malfunctions despite a
good UDP connection. The network-side recipient buffer will overflow without the re-
cipient being able to indicate an interval signal to the sender.
5.3 Remote configuration
In addition to the offline command mode, the INSYS Ethernet can also accept all AT
commands via Telnet remote configuration.
This function is available offline, or online for an existing data connection.
Please find a detailed description of this function in Chapter Fehler! Verweisquelle konn-
te nicht gefunden werden..
5.4 I/O Tunneling
In this operating mode, the signals at the inputs of an INSYS Ethernet are automatically
transmitted to the outputs of a second INSYS Ethernet.
This function is available offline, or online for an existing data connection (only TCP!).
Please find a detailed description of this function in Chapter Fehler! Verweisquelle konn-
te nicht gefunden werden..