Somerdata AROW Series, Additional Instructions For Installation And Operation

Page: 35 / 82

AROW Series
Data Diode
Installation and Operation 6-11
The Diode contains a significant data buffer, capable of storing up to 2
seconds worth of data at full transfer rates. If the high side is summarily
disconnected, but the low side continues to receive data, this buffer will
fill, and data transfer will stop. On reconnection of the High side, the
stored data will be transferred before any new data is received, meaning
that the received data will be discontinuous, containing a buffer’s worth of
data. This can cause significant problems to downstream data
processing equipment, depending on the type of data being transferred.
Also, this will increase the latency of data across the diode, which will be
permanent until the sending side is reset.
For these reasons, the correct sequence of software processing to
achieve the lowest latency and no corrupted data
Connecting
1. Start the High (receive) side processing software and establish the
socket connection.
2. Start the Low (send) side software .
Disconnecting
3. Stop the Low(send) side software and disconnect the network.
4. Stop the receive side software and disconnect the network.
Recovering a socket connection after unscheduled disconnect.
The abrupt disconnection of the Ethernet connection while powered can
cause the Data socket to stop responding. This can be recovered by
using the control port of the module to send reset commands.
First, stop any running software that is accessing the locked socket.
If you are using WinAROW to monitor the receive module, this is simply
accomplished by clicking the TCP rst reset button on the main screen,
then the Connect button on the setup screen.
If you have implemented your own control program, you should add the
ability to reset the TCP socket, and combine it with setting of the Data
socket IP address, Mask and Gateway Address.